diff --git a/dist/action-sheet/index.js b/dist/action-sheet/index.js
index 667cdfc5..8065c833 100644
--- a/dist/action-sheet/index.js
+++ b/dist/action-sheet/index.js
@@ -4,6 +4,7 @@ VantComponent({
         show: Boolean,
         title: String,
         cancelText: String,
+        description: String,
         round: {
             type: Boolean,
             value: true
diff --git a/dist/action-sheet/index.wxml b/dist/action-sheet/index.wxml
index c5bbf685..2dcbf4f8 100644
--- a/dist/action-sheet/index.wxml
+++ b/dist/action-sheet/index.wxml
@@ -19,6 +19,9 @@
       bind:click="onClose"
     />
   </view>
+  <view wx:if="{{ description }}" class="van-action-sheet__description">
+    {{ description }}
+  </view>
   <view wx:if="{{ actions && actions.length }}">
     <!-- button外包一层view，防止actions动态变化，导致渲染时button被打散 -->
     <button
diff --git a/dist/action-sheet/index.wxss b/dist/action-sheet/index.wxss
index f88ad2a8..c40c051d 100644
--- a/dist/action-sheet/index.wxss
+++ b/dist/action-sheet/index.wxss
@@ -1 +1 @@
-@import '../common/index.wxss';.van-action-sheet{max-height:90%!important;color:#333;color:var(--text-color,#333)}.van-action-sheet__cancel,.van-action-sheet__item{height:50px;font-size:16px;line-height:50px;text-align:center;background-color:#fff;background-color:var(--white,#fff)}.van-action-sheet__cancel--hover,.van-action-sheet__item--hover{background-color:#f2f3f5;background-color:var(--active-color,#f2f3f5)}.van-action-sheet__cancel{height:60px}.van-action-sheet__cancel:before{display:block;height:10px;content:" ";background-color:#f8f8f8;background-color:var(--background-color,#f8f8f8)}.van-action-sheet__item--disabled{color:#c9c9c9;color:var(--gray,#c9c9c9)}.van-action-sheet__item--disabled.van-action-sheet__item--hover{background-color:#fff;background-color:var(--white,#fff)}.van-action-sheet__subname{margin-left:5px;font-size:12px;color:#7d7e80;color:var(--gray-darker,#7d7e80)}.van-action-sheet__header{font-weight:500;font-size:16px;line-height:44px;text-align:center}.van-action-sheet__close{position:absolute!important;top:0;right:0;padding:0 15px;font-size:18px!important;line-height:inherit!important;color:#999;color:var(--gray-dark,#999)}
\ No newline at end of file
+@import '../common/index.wxss';.van-action-sheet{max-height:90%!important;color:#333;color:var(--text-color,#333)}.van-action-sheet__cancel,.van-action-sheet__item{height:50px;font-size:16px;line-height:50px;text-align:center;background-color:#fff;background-color:var(--white,#fff)}.van-action-sheet__cancel--hover,.van-action-sheet__item--hover{background-color:#f2f3f5;background-color:var(--active-color,#f2f3f5)}.van-action-sheet__cancel{height:60px}.van-action-sheet__cancel:before{display:block;height:10px;content:" ";background-color:#f8f8f8;background-color:var(--background-color,#f8f8f8)}.van-action-sheet__item--disabled{color:#c9c9c9;color:var(--gray,#c9c9c9)}.van-action-sheet__item--disabled.van-action-sheet__item--hover{background-color:#fff;background-color:var(--white,#fff)}.van-action-sheet__subname{margin-left:5px;font-size:12px;color:#7d7e80;color:var(--gray-darker,#7d7e80)}.van-action-sheet__header{font-weight:500;font-size:16px;line-height:44px;text-align:center}.van-action-sheet__description{padding:16px;color:#7d7e80;font-size:14px;line-height:20px;text-align:center}.van-action-sheet__close{position:absolute!important;top:0;right:0;padding:0 15px;font-size:18px!important;line-height:inherit!important;color:#999;color:var(--gray-dark,#999)}
\ No newline at end of file
diff --git a/dist/area/index.js b/dist/area/index.js
index ac8bbadb..0e7cd6dd 100644
--- a/dist/area/index.js
+++ b/dist/area/index.js
@@ -1,5 +1,6 @@
 import { VantComponent } from '../common/component';
 import { pickerProps } from '../picker/shared';
+const COLUMNSPLACEHOLDERCODE = '000000';
 VantComponent({
     classes: ['active-class', 'toolbar-class', 'column-class'],
     props: Object.assign(Object.assign({}, pickerProps), { value: String, areaList: {
@@ -8,10 +9,22 @@ VantComponent({
         }, columnsNum: {
             type: null,
             value: 3
+        }, columnsPlaceholder: {
+            type: Array,
+            observer(val) {
+                this.setData({
+                    typeToColumnsPlaceholder: {
+                        province: val[0] || '',
+                        city: val[1] || '',
+                        county: val[2] || '',
+                    }
+                });
+            }
         } }),
     data: {
         columns: [{ values: [] }, { values: [] }, { values: [] }],
-        displayColumns: [{ values: [] }, { values: [] }, { values: [] }]
+        displayColumns: [{ values: [] }, { values: [] }, { values: [] }],
+        typeToColumnsPlaceholder: {}
     },
     watch: {
         value(value) {
@@ -41,20 +54,37 @@ VantComponent({
             this.emit('cancel', event.detail);
         },
         onConfirm(event) {
-            this.emit('confirm', event.detail);
+            const { index } = event.detail;
+            let { value } = event.detail;
+            value = this.parseOutputValues(value);
+            this.emit('confirm', { value, index });
         },
         emit(type, detail) {
             detail.values = detail.value;
             delete detail.value;
             this.$emit(type, detail);
         },
+        // parse output columns data
+        parseOutputValues(values) {
+            const { columnsPlaceholder } = this.data;
+            return values.map((value = {}, index) => {
+                value = JSON.parse(JSON.stringify(value));
+                if (!value.code || value.name === columnsPlaceholder[index]) {
+                    value.code = '';
+                    value.name = '';
+                }
+                return value;
+            });
+        },
         onChange(event) {
             const { index, picker, value } = event.detail;
             this.code = value[index].code;
+            let getValues = picker.getValues();
+            getValues = this.parseOutputValues(getValues);
             this.setValues().then(() => {
                 this.$emit('change', {
                     picker,
-                    values: picker.getValues(),
+                    values: getValues,
                     index
                 });
             });
@@ -64,6 +94,7 @@ VantComponent({
             return (areaList && areaList[`${type}_list`]) || {};
         },
         getList(type, code) {
+            const { typeToColumnsPlaceholder } = this.data;
             let result = [];
             if (type !== 'province' && !code) {
                 return result;
@@ -80,6 +111,14 @@ VantComponent({
                 }
                 result = result.filter(item => item.code.indexOf(code) === 0);
             }
+            if (typeToColumnsPlaceholder[type] && result.length) {
+                // set columns placeholder
+                const codeFill = type === 'province' ? '' : type === 'city' ? COLUMNSPLACEHOLDERCODE.slice(2, 4) : COLUMNSPLACEHOLDERCODE.slice(4, 6);
+                result.unshift({
+                    code: `${code}${codeFill}`,
+                    name: typeToColumnsPlaceholder[type]
+                });
+            }
             return result;
         },
         getIndex(type, code) {
@@ -99,7 +138,18 @@ VantComponent({
         },
         setValues() {
             const county = this.getConfig('county');
-            let code = this.code || Object.keys(county)[0] || '';
+            let { code } = this;
+            if (!code) {
+                if (this.data.columnsPlaceholder.length) {
+                    code = COLUMNSPLACEHOLDERCODE;
+                }
+                else if (Object.keys(county)[0]) {
+                    code = Object.keys(county)[0];
+                }
+                else {
+                    code = '';
+                }
+            }
             const province = this.getList('province');
             const city = this.getList('city', code.slice(0, 2));
             const picker = this.getPicker();
diff --git a/dist/count-down/index.d.ts b/dist/count-down/index.d.ts
new file mode 100644
index 00000000..cb0ff5c3
--- /dev/null
+++ b/dist/count-down/index.d.ts
@@ -0,0 +1 @@
+export {};
diff --git a/dist/count-down/index.js b/dist/count-down/index.js
new file mode 100644
index 00000000..17bd3ca7
--- /dev/null
+++ b/dist/count-down/index.js
@@ -0,0 +1,96 @@
+import { VantComponent } from '../common/component';
+import { isSameSecond, parseFormat, parseTimeData } from './utils';
+function simpleTick(fn) {
+    return setTimeout(fn, 30);
+}
+VantComponent({
+    props: {
+        useSlot: Boolean,
+        millisecond: Boolean,
+        time: {
+            type: Number,
+            observer: 'reset'
+        },
+        format: {
+            type: String,
+            value: 'HH:mm:ss'
+        },
+        autoStart: {
+            type: Boolean,
+            value: true
+        }
+    },
+    data: {
+        timeData: parseTimeData(0),
+        formattedTime: '0'
+    },
+    methods: {
+        // 开始
+        start() {
+            if (this.counting) {
+                return;
+            }
+            this.counting = true;
+            this.endTime = Date.now() + this.remain;
+            this.tick();
+        },
+        // 暂停
+        pause() {
+            this.counting = false;
+            clearTimeout(this.tid);
+        },
+        // 重置
+        reset() {
+            this.pause();
+            this.remain = this.data.time;
+            this.setRemain(this.remain);
+            if (this.data.autoStart) {
+                this.start();
+            }
+        },
+        tick() {
+            if (this.data.millisecond) {
+                this.microTick();
+            }
+            else {
+                this.macroTick();
+            }
+        },
+        microTick() {
+            this.tid = simpleTick(() => {
+                this.setRemain(this.getRemain());
+                if (this.remain !== 0) {
+                    this.microTick();
+                }
+            });
+        },
+        macroTick() {
+            this.tid = simpleTick(() => {
+                const remain = this.getRemain();
+                if (!isSameSecond(remain, this.remain) || remain === 0) {
+                    this.setRemain(remain);
+                }
+                if (this.remain !== 0) {
+                    this.macroTick();
+                }
+            });
+        },
+        getRemain() {
+            return Math.max(this.endTime - Date.now(), 0);
+        },
+        setRemain(remain) {
+            this.remain = remain;
+            const timeData = parseTimeData(remain);
+            if (this.data.useSlot) {
+                this.$emit('change', timeData);
+            }
+            this.setData({
+                formattedTime: parseFormat(this.data.format, timeData)
+            });
+            if (remain === 0) {
+                this.pause();
+                this.$emit('finish');
+            }
+        }
+    }
+});
diff --git a/dist/count-down/index.json b/dist/count-down/index.json
new file mode 100644
index 00000000..467ce294
--- /dev/null
+++ b/dist/count-down/index.json
@@ -0,0 +1,3 @@
+{
+  "component": true
+}
diff --git a/dist/count-down/index.wxml b/dist/count-down/index.wxml
new file mode 100644
index 00000000..e206e167
--- /dev/null
+++ b/dist/count-down/index.wxml
@@ -0,0 +1,4 @@
+<view class="van-count-down">
+  <slot wx:if="{{ useSlot }}"/>
+  <block wx:else>{{ formattedTime }}</block>
+</view>
diff --git a/dist/count-down/index.wxss b/dist/count-down/index.wxss
new file mode 100644
index 00000000..275d5739
--- /dev/null
+++ b/dist/count-down/index.wxss
@@ -0,0 +1 @@
+@import '../common/index.wxss';.van-count-down{color:#333;font-size:14px;line-height:20px}
\ No newline at end of file
diff --git a/dist/count-down/utils.d.ts b/dist/count-down/utils.d.ts
new file mode 100644
index 00000000..e4a58ddf
--- /dev/null
+++ b/dist/count-down/utils.d.ts
@@ -0,0 +1,10 @@
+export declare type TimeData = {
+    days: number;
+    hours: number;
+    minutes: number;
+    seconds: number;
+    milliseconds: number;
+};
+export declare function parseTimeData(time: number): TimeData;
+export declare function parseFormat(format: string, timeData: TimeData): string;
+export declare function isSameSecond(time1: number, time2: number): boolean;
diff --git a/dist/count-down/utils.js b/dist/count-down/utils.js
new file mode 100644
index 00000000..32379881
--- /dev/null
+++ b/dist/count-down/utils.js
@@ -0,0 +1,57 @@
+function padZero(num, targetLength = 2) {
+    let str = num + '';
+    while (str.length < targetLength) {
+        str = '0' + str;
+    }
+    return str;
+}
+const SECOND = 1000;
+const MINUTE = 60 * SECOND;
+const HOUR = 60 * MINUTE;
+const DAY = 24 * HOUR;
+export function parseTimeData(time) {
+    const days = Math.floor(time / DAY);
+    const hours = Math.floor((time % DAY) / HOUR);
+    const minutes = Math.floor((time % HOUR) / MINUTE);
+    const seconds = Math.floor((time % MINUTE) / SECOND);
+    const milliseconds = Math.floor(time % SECOND);
+    return {
+        days,
+        hours,
+        minutes,
+        seconds,
+        milliseconds
+    };
+}
+export function parseFormat(format, timeData) {
+    const { days } = timeData;
+    let { hours, minutes, seconds, milliseconds } = timeData;
+    if (format.indexOf('DD') === -1) {
+        hours += days * 24;
+    }
+    else {
+        format = format.replace('DD', padZero(days));
+    }
+    if (format.indexOf('HH') === -1) {
+        minutes += hours * 60;
+    }
+    else {
+        format = format.replace('HH', padZero(hours));
+    }
+    if (format.indexOf('mm') === -1) {
+        seconds += minutes * 60;
+    }
+    else {
+        format = format.replace('mm', padZero(minutes));
+    }
+    if (format.indexOf('ss') === -1) {
+        milliseconds += seconds * 1000;
+    }
+    else {
+        format = format.replace('ss', padZero(seconds));
+    }
+    return format.replace('SSS', padZero(milliseconds, 3));
+}
+export function isSameSecond(time1, time2) {
+    return Math.floor(time1 / 1000) === Math.floor(time2 / 1000);
+}
diff --git a/dist/dialog/dialog.d.ts b/dist/dialog/dialog.d.ts
index 028077ab..66769a6d 100644
--- a/dist/dialog/dialog.d.ts
+++ b/dist/dialog/dialog.d.ts
@@ -4,6 +4,7 @@ declare type DialogOptions = {
     lang?: string;
     show?: boolean;
     title?: string;
+    width?: string | number;
     zIndex?: number;
     context?: WechatMiniprogram.Page.TrivialInstance | WechatMiniprogram.Component.TrivialInstance;
     message?: string;
@@ -16,6 +17,7 @@ declare type DialogOptions = {
     asyncClose?: boolean;
     businessId?: number;
     sessionFrom?: string;
+    overlayStyle?: string;
     appParameter?: string;
     messageAlign?: string;
     sendMessageImg?: string;
diff --git a/dist/dialog/dialog.js b/dist/dialog/dialog.js
index 5f55f3d2..4c4f7e47 100644
--- a/dist/dialog/dialog.js
+++ b/dist/dialog/dialog.js
@@ -22,15 +22,17 @@ const Dialog = options => {
 Dialog.defaultOptions = {
     show: true,
     title: '',
+    width: null,
     message: '',
     zIndex: 100,
     overlay: true,
-    className: '',
-    customStyle: '',
-    asyncClose: false,
-    messageAlign: '',
-    transition: 'scale',
     selector: '#van-dialog',
+    className: '',
+    asyncClose: false,
+    transition: 'scale',
+    customStyle: '',
+    messageAlign: '',
+    overlayStyle: '',
     confirmButtonText: '确认',
     cancelButtonText: '取消',
     showConfirmButton: true,
diff --git a/dist/dialog/index.js b/dist/dialog/index.js
index fc300bd3..85d6c3c1 100644
--- a/dist/dialog/index.js
+++ b/dist/dialog/index.js
@@ -1,6 +1,7 @@
 import { VantComponent } from '../common/component';
 import { button } from '../mixins/button';
 import { openType } from '../mixins/open-type';
+import { addUnit } from '../common/utils';
 import { GRAY, BLUE } from '../common/color';
 VantComponent({
     mixins: [button, openType],
@@ -13,10 +14,15 @@ VantComponent({
         customStyle: String,
         asyncClose: Boolean,
         messageAlign: String,
+        overlayStyle: String,
         useTitleSlot: Boolean,
         showCancelButton: Boolean,
         closeOnClickOverlay: Boolean,
         confirmButtonOpenType: String,
+        width: {
+            type: null,
+            observer: 'setWidthWithUnit'
+        },
         zIndex: {
             type: Number,
             value: 2000
@@ -103,6 +109,11 @@ VantComponent({
             if (callback) {
                 callback(this);
             }
+        },
+        setWidthWithUnit(val) {
+            this.setData({
+                widthWithUnit: addUnit(val)
+            });
         }
     }
 });
diff --git a/dist/dialog/index.wxml b/dist/dialog/index.wxml
index 1f02b3d8..854e8a14 100644
--- a/dist/dialog/index.wxml
+++ b/dist/dialog/index.wxml
@@ -2,9 +2,10 @@
   show="{{ show }}"
   z-index="{{ zIndex }}"
   overlay="{{ overlay }}"
-  custom-class="van-dialog {{ className }}"
   transition="{{ transition }}"
-  custom-style="{{ customStyle }}"
+  custom-class="van-dialog {{ className }}"
+  custom-style="{{ widthWithUnit ? 'width: ' + widthWithUnit + ';' : '' }}{{ customStyle }}"
+  overlay-style="{{ overlayStyle }}"
   close-on-click-overlay="{{ closeOnClickOverlay }}"
   bind:close="onClickOverlay"
 >
diff --git a/dist/dialog/index.wxss b/dist/dialog/index.wxss
index c7a331d4..869c5c35 100644
--- a/dist/dialog/index.wxss
+++ b/dist/dialog/index.wxss
@@ -1 +1 @@
-@import '../common/index.wxss';.van-dialog{top:45%!important;width:85%;overflow:hidden;font-size:16px;border-radius:4px;background-color:#fff;background-color:var(--white,#fff)}.van-dialog__header{padding-top:25px;font-weight:500;line-height:24px;text-align:center}.van-dialog__header--isolated{padding:25px 0}.van-dialog__message{max-height:60vh;padding:25px;overflow-y:auto;font-size:14px;line-height:20px;text-align:center;-webkit-overflow-scrolling:touch}.van-dialog__message-text{word-wrap:break-word}.van-dialog__message--has-title{padding-top:12px;color:#7d7e80;color:var(--gray-darker,#7d7e80)}.van-dialog__message--left{text-align:left}.van-dialog__message--right{text-align:right}.van-dialog__footer{display:-webkit-flex;display:flex}.van-dialog__button{-webkit-flex:1;flex:1}.van-dialog__cancel,.van-dialog__confirm{border:0!important}.van-dialog-bounce-enter{-webkit-transform:translate3d(-50%,-50%,0) scale(.7);transform:translate3d(-50%,-50%,0) scale(.7);opacity:0}.van-dialog-bounce-leave-active{-webkit-transform:translate3d(-50%,-50%,0) scale(.9);transform:translate3d(-50%,-50%,0) scale(.9);opacity:0}
\ No newline at end of file
+@import '../common/index.wxss';.van-dialog{top:45%!important;width:320px;overflow:hidden;font-size:16px;border-radius:4px;background-color:#fff;background-color:var(--white,#fff)}@media (max-width:321px){.van-dialog{width:90%}}.van-dialog__header{padding-top:25px;font-weight:500;line-height:24px;text-align:center}.van-dialog__header--isolated{padding:25px 0}.van-dialog__message{max-height:60vh;padding:25px;overflow-y:auto;font-size:14px;line-height:20px;text-align:center;-webkit-overflow-scrolling:touch}.van-dialog__message-text{word-wrap:break-word}.van-dialog__message--has-title{padding-top:12px;color:#7d7e80;color:var(--gray-darker,#7d7e80)}.van-dialog__message--left{text-align:left}.van-dialog__message--right{text-align:right}.van-dialog__footer{display:-webkit-flex;display:flex}.van-dialog__button{-webkit-flex:1;flex:1}.van-dialog__cancel,.van-dialog__confirm{border:0!important}.van-dialog-bounce-enter{-webkit-transform:translate3d(-50%,-50%,0) scale(.7);transform:translate3d(-50%,-50%,0) scale(.7);opacity:0}.van-dialog-bounce-leave-active{-webkit-transform:translate3d(-50%,-50%,0) scale(.9);transform:translate3d(-50%,-50%,0) scale(.9);opacity:0}
\ No newline at end of file
diff --git a/dist/loading/index.js b/dist/loading/index.js
index e0952fac..ef80c32a 100644
--- a/dist/loading/index.js
+++ b/dist/loading/index.js
@@ -13,16 +13,27 @@ VantComponent({
         color: {
             type: String,
             value: '#c9c9c9'
-        }
+        },
+        textSize: {
+            type: String,
+            observer: 'setTextSizeWithUnit'
+        },
+        vertical: Boolean
     },
     data: {
-        sizeWithUnit: '30px'
+        sizeWithUnit: '30px',
+        textSizeWithUnit: '14px'
     },
     methods: {
         setSizeWithUnit(size) {
             this.setData({
                 sizeWithUnit: addUnit(size)
             });
+        },
+        setTextSizeWithUnit(size) {
+            this.set({
+                textSizeWithUnit: addUnit(size)
+            });
         }
     }
 });
diff --git a/dist/loading/index.wxml b/dist/loading/index.wxml
index ff329466..88b0148f 100644
--- a/dist/loading/index.wxml
+++ b/dist/loading/index.wxml
@@ -1,16 +1,24 @@
-<view
-  class="van-loading custom-class"
-  style="width: {{ sizeWithUnit }}; height: {{ sizeWithUnit }}"
->
+<view class="van-loading {{vertical ? 'van-loading--vertical' : ''}}">
   <view
-    class="van-loading__spinner van-loading__spinner--{{ type }}"
-    style="color: {{ color }};"
+    class="van-loading__wrapper custom-class"
+    style="width: {{ sizeWithUnit }}; height: {{ sizeWithUnit }}"
   >
     <view
-      wx:if="{{ type === 'spinner' }}"
-      wx:for="item in 12"
-      wx:key="index"
-      class="van-loading__dot"
-    />
+      class="van-loading__spinner van-loading__spinner--{{ type }}"
+      style="color: {{ color }};"
+    >
+      <view
+        wx:if="{{ type === 'spinner' }}"
+        wx:for="item in 12"
+        wx:key="index"
+        class="van-loading__dot"
+      />
+    </view>
+  </view>
+  <view 
+    style="font-size: {{textSizeWithUnit}};" 
+    class="van-loading__text {{vertical ? 'van-loading__text--vertical' : ''}}"
+  >
+    <slot />
   </view>
 </view>
\ No newline at end of file
diff --git a/dist/loading/index.wxss b/dist/loading/index.wxss
index 43ffdafa..64ceff23 100644
--- a/dist/loading/index.wxss
+++ b/dist/loading/index.wxss
@@ -1 +1 @@
-@import '../common/index.wxss';.van-loading{z-index:0;line-height:0;vertical-align:middle}.van-loading,.van-loading__spinner{position:relative;display:inline-block}.van-loading__spinner{z-index:-1;box-sizing:border-box;width:100%;height:100%;-webkit-animation:van-rotate .8s linear infinite;animation:van-rotate .8s linear infinite}.van-loading__spinner--spinner{-webkit-animation-timing-function:steps(12);animation-timing-function:steps(12)}.van-loading__spinner--circular{border:1px solid transparent;border-top-color:initial;border-radius:100%}.van-loading__dot{position:absolute;top:0;left:0;width:100%;height:100%}.van-loading__dot:before{display:block;width:2px;height:25%;margin:0 auto;background-color:currentColor;border-radius:40%;content:" "}.van-loading__dot:first-of-type{-webkit-transform:rotate(30deg);transform:rotate(30deg);opacity:1}.van-loading__dot:nth-of-type(2){-webkit-transform:rotate(60deg);transform:rotate(60deg);opacity:.9375}.van-loading__dot:nth-of-type(3){-webkit-transform:rotate(90deg);transform:rotate(90deg);opacity:.875}.van-loading__dot:nth-of-type(4){-webkit-transform:rotate(120deg);transform:rotate(120deg);opacity:.8125}.van-loading__dot:nth-of-type(5){-webkit-transform:rotate(150deg);transform:rotate(150deg);opacity:.75}.van-loading__dot:nth-of-type(6){-webkit-transform:rotate(180deg);transform:rotate(180deg);opacity:.6875}.van-loading__dot:nth-of-type(7){-webkit-transform:rotate(210deg);transform:rotate(210deg);opacity:.625}.van-loading__dot:nth-of-type(8){-webkit-transform:rotate(240deg);transform:rotate(240deg);opacity:.5625}.van-loading__dot:nth-of-type(9){-webkit-transform:rotate(270deg);transform:rotate(270deg);opacity:.5}.van-loading__dot:nth-of-type(10){-webkit-transform:rotate(300deg);transform:rotate(300deg);opacity:.4375}.van-loading__dot:nth-of-type(11){-webkit-transform:rotate(330deg);transform:rotate(330deg);opacity:.375}.van-loading__dot:nth-of-type(12){-webkit-transform:rotate(1turn);transform:rotate(1turn);opacity:.3125}@-webkit-keyframes van-rotate{0%{-webkit-transform:rotate(0deg);transform:rotate(0deg)}to{-webkit-transform:rotate(1turn);transform:rotate(1turn)}}@keyframes van-rotate{0%{-webkit-transform:rotate(0deg);transform:rotate(0deg)}to{-webkit-transform:rotate(1turn);transform:rotate(1turn)}}
\ No newline at end of file
+@import '../common/index.wxss';.van-loading{display:-webkit-inline-flex;display:inline-flex;-webkit-align-items:center;align-items:center;-webkit-justify-content:center;justify-content:center}.van-loading__wrapper{position:relative;z-index:0;display:inline-block;line-height:0}.van-loading--vertical{-webkit-flex-direction:column;flex-direction:column}.van-loading__spinner{position:relative;z-index:-1;display:inline-block;box-sizing:border-box;width:100%;height:100%;-webkit-animation:van-rotate .8s linear infinite;animation:van-rotate .8s linear infinite}.van-loading__spinner--spinner{-webkit-animation-timing-function:steps(12);animation-timing-function:steps(12)}.van-loading__spinner--circular{border:1px solid transparent;border-top-color:initial;border-radius:100%}.van-loading__text{margin-left:8px;color:#969799}.van-loading__text--vertical{margin:8px 0 0}.van-loading__dot{position:absolute;top:0;left:0;width:100%;height:100%}.van-loading__dot:before{display:block;width:2px;height:25%;margin:0 auto;background-color:currentColor;border-radius:40%;content:" "}.van-loading__dot:first-of-type{-webkit-transform:rotate(30deg);transform:rotate(30deg);opacity:1}.van-loading__dot:nth-of-type(2){-webkit-transform:rotate(60deg);transform:rotate(60deg);opacity:.9375}.van-loading__dot:nth-of-type(3){-webkit-transform:rotate(90deg);transform:rotate(90deg);opacity:.875}.van-loading__dot:nth-of-type(4){-webkit-transform:rotate(120deg);transform:rotate(120deg);opacity:.8125}.van-loading__dot:nth-of-type(5){-webkit-transform:rotate(150deg);transform:rotate(150deg);opacity:.75}.van-loading__dot:nth-of-type(6){-webkit-transform:rotate(180deg);transform:rotate(180deg);opacity:.6875}.van-loading__dot:nth-of-type(7){-webkit-transform:rotate(210deg);transform:rotate(210deg);opacity:.625}.van-loading__dot:nth-of-type(8){-webkit-transform:rotate(240deg);transform:rotate(240deg);opacity:.5625}.van-loading__dot:nth-of-type(9){-webkit-transform:rotate(270deg);transform:rotate(270deg);opacity:.5}.van-loading__dot:nth-of-type(10){-webkit-transform:rotate(300deg);transform:rotate(300deg);opacity:.4375}.van-loading__dot:nth-of-type(11){-webkit-transform:rotate(330deg);transform:rotate(330deg);opacity:.375}.van-loading__dot:nth-of-type(12){-webkit-transform:rotate(1turn);transform:rotate(1turn);opacity:.3125}@-webkit-keyframes van-rotate{0%{-webkit-transform:rotate(0deg);transform:rotate(0deg)}to{-webkit-transform:rotate(1turn);transform:rotate(1turn)}}@keyframes van-rotate{0%{-webkit-transform:rotate(0deg);transform:rotate(0deg)}to{-webkit-transform:rotate(1turn);transform:rotate(1turn)}}
\ No newline at end of file
diff --git a/dist/mixins/transition.js b/dist/mixins/transition.js
index e5bd4fea..a64df6ab 100644
--- a/dist/mixins/transition.js
+++ b/dist/mixins/transition.js
@@ -39,22 +39,19 @@ export const transition = function (showDefaultValue) {
         },
         methods: {
             observeShow(value) {
-                if (value) {
-                    this.enter();
-                }
-                else {
-                    this.leave();
-                }
+                value ? this.enter() : this.leave();
             },
             enter() {
                 const { duration, name } = this.data;
                 const classNames = getClassNames(name);
                 const currentDuration = isObj(duration) ? duration.enter : duration;
                 this.status = 'enter';
+                this.$emit('before-enter');
                 Promise.resolve()
                     .then(nextTick)
                     .then(() => {
                     this.checkStatus('enter');
+                    this.$emit('enter');
                     this.setData({
                         inited: true,
                         display: true,
@@ -65,6 +62,7 @@ export const transition = function (showDefaultValue) {
                     .then(nextTick)
                     .then(() => {
                     this.checkStatus('enter');
+                    this.transitionEnded = false;
                     this.setData({
                         classes: classNames['enter-to']
                     });
@@ -72,23 +70,29 @@ export const transition = function (showDefaultValue) {
                     .catch(() => { });
             },
             leave() {
+                if (!this.data.display) {
+                    return;
+                }
                 const { duration, name } = this.data;
                 const classNames = getClassNames(name);
                 const currentDuration = isObj(duration) ? duration.leave : duration;
                 this.status = 'leave';
+                this.$emit('before-leave');
                 Promise.resolve()
                     .then(nextTick)
                     .then(() => {
                     this.checkStatus('leave');
+                    this.$emit('leave');
                     this.setData({
                         classes: classNames.leave,
                         currentDuration
                     });
                 })
-                    .then(() => setTimeout(() => this.onTransitionEnd(), currentDuration))
                     .then(nextTick)
                     .then(() => {
                     this.checkStatus('leave');
+                    this.transitionEnded = false;
+                    setTimeout(() => this.onTransitionEnd(), currentDuration);
                     this.setData({
                         classes: classNames['leave-to']
                     });
@@ -101,9 +105,14 @@ export const transition = function (showDefaultValue) {
                 }
             },
             onTransitionEnd() {
-                if (!this.data.show) {
-                    this.set({ display: false });
-                    this.$emit('transitionend');
+                if (this.transitionEnded) {
+                    return;
+                }
+                this.transitionEnded = true;
+                this.$emit(`after-${this.status}`);
+                const { show, display } = this.data;
+                if (!show && display) {
+                    this.setData({ display: false });
                 }
             }
         }
diff --git a/dist/nav-bar/index.js b/dist/nav-bar/index.js
index c7f93202..3acf41a8 100644
--- a/dist/nav-bar/index.js
+++ b/dist/nav-bar/index.js
@@ -20,6 +20,13 @@ VantComponent({
             value: true
         },
     },
+    data: {
+        statusBarHeight: 0
+    },
+    created() {
+        const { statusBarHeight } = wx.getSystemInfoSync();
+        this.setData({ statusBarHeight });
+    },
     methods: {
         onClickLeft() {
             this.$emit('click-left');
diff --git a/dist/nav-bar/index.wxml b/dist/nav-bar/index.wxml
index b3690aeb..9ed4446f 100644
--- a/dist/nav-bar/index.wxml
+++ b/dist/nav-bar/index.wxml
@@ -1,8 +1,8 @@
 <wxs src="../wxs/utils.wxs" module="utils" />
 
 <view
-  class="{{ utils.bem('nav-bar', { fixed, safe: safeAreaInsetTop }) }} custom-class {{ border ? 'van-hairline--bottom' : '' }}"
-  style="z-index: {{ zIndex }};"
+  class="{{ utils.bem('nav-bar', { fixed }) }} custom-class {{ border ? 'van-hairline--bottom' : '' }}"
+  style="z-index: {{ zIndex }}; padding-top: {{ safeAreaInsetTop ? statusBarHeight : 0 }}px;"
 >
   <view class="van-nav-bar__left" bind:tap="onClickLeft">
     <block wx:if="{{ leftArrow || leftText }}">
diff --git a/dist/nav-bar/index.wxss b/dist/nav-bar/index.wxss
index b3c344a5..1ba28ea7 100644
--- a/dist/nav-bar/index.wxss
+++ b/dist/nav-bar/index.wxss
@@ -1 +1 @@
-@import '../common/index.wxss';.van-nav-bar{position:relative;text-align:center;-webkit-user-select:none;user-select:none;height:44px;height:var(--nav-bar-height,44px);line-height:44px;line-height:var(--nav-bar-height,44px);background-color:#fff;background-color:var(--white,#fff)}.van-nav-bar--safe{padding-top:env(safe-area-inset-top)}.van-nav-bar__text{display:inline-block;margin:0 -15px;padding:0 15px;vertical-align:middle;color:#1989fa;color:var(--blue,#1989fa)}.van-nav-bar__text--hover{background-color:#f2f3f5;background-color:var(--active-color,#f2f3f5)}.van-nav-bar__arrow{vertical-align:middle;color:#1989fa;color:var(--blue,#1989fa)}.van-nav-bar__arrow+.van-nav-bar__text{margin-left:-20px;padding-left:25px}.van-nav-bar--fixed{position:fixed;top:0;left:0;width:100%}.van-nav-bar__title{max-width:60%;margin:0 auto;font-weight:500;font-size:16px}.van-nav-bar__left,.van-nav-bar__right{position:absolute;bottom:0;font-size:14px}.van-nav-bar__left{left:15px}.van-nav-bar__right{right:15px}
\ No newline at end of file
+@import '../common/index.wxss';.van-nav-bar{position:relative;text-align:center;-webkit-user-select:none;user-select:none;height:44px;height:var(--nav-bar-height,44px);line-height:44px;line-height:var(--nav-bar-height,44px);background-color:#fff;background-color:var(--white,#fff)}.van-nav-bar__text{display:inline-block;margin:0 -15px;padding:0 15px;vertical-align:middle;color:#1989fa;color:var(--blue,#1989fa)}.van-nav-bar__text--hover{background-color:#f2f3f5;background-color:var(--active-color,#f2f3f5)}.van-nav-bar__arrow{vertical-align:middle;color:#1989fa;color:var(--blue,#1989fa)}.van-nav-bar__arrow+.van-nav-bar__text{margin-left:-20px;padding-left:25px}.van-nav-bar--fixed{position:fixed;top:0;left:0;width:100%}.van-nav-bar__title{max-width:60%;margin:0 auto;font-weight:500;font-size:16px}.van-nav-bar__left,.van-nav-bar__right{position:absolute;bottom:0;font-size:14px}.van-nav-bar__left{left:15px}.van-nav-bar__right{right:15px}
\ No newline at end of file
diff --git a/dist/rate/index.wxss b/dist/rate/index.wxss
index acc13946..4538752e 100644
--- a/dist/rate/index.wxss
+++ b/dist/rate/index.wxss
@@ -1 +1 @@
-@import '../common/index.wxss';.van-rate{display:inline-block;-webkit-user-select:none;user-select:none}.van-rate__item{position:relative;display:inline-block;padding:0 2px;padding:0 var(--rate-horizontal-padding,2px)}.van-rate__icon{display:block;height:1em}.van-rate__icon--half{position:absolute;top:0;width:.5em;overflow:hidden;left:2px;left:var(--rate-horizontal-padding,2px)}
\ No newline at end of file
+@import '../common/index.wxss';.van-rate{display:-webkit-inline-flex;display:inline-flex;-webkit-user-select:none;user-select:none}.van-rate__item{position:relative;padding:0 2px;padding:0 var(--rate-horizontal-padding,2px)}.van-rate__icon{display:block;height:1em}.van-rate__icon--half{position:absolute;top:0;width:.5em;overflow:hidden;left:2px;left:var(--rate-horizontal-padding,2px)}
\ No newline at end of file
diff --git a/dist/slider/index.js b/dist/slider/index.js
index b454f617..971e15e0 100644
--- a/dist/slider/index.js
+++ b/dist/slider/index.js
@@ -82,7 +82,11 @@ VantComponent({
             const width = `${((value - min) * 100) / this.getRange()}%`;
             this.setData({
                 value,
-                barStyle: `width: ${width}; height: ${addUnit(barHeight)};`
+                barStyle: `
+          width: ${width};
+          height: ${addUnit(barHeight)};
+          ${drag ? 'transition: none;' : ''}
+        `,
             });
             if (drag) {
                 this.$emit('drag', { value });
diff --git a/dist/slider/index.wxss b/dist/slider/index.wxss
index 28d5bff1..85681030 100644
--- a/dist/slider/index.wxss
+++ b/dist/slider/index.wxss
@@ -1 +1 @@
-@import '../common/index.wxss';.van-slider{position:relative;border-radius:999px;background-color:#e5e5e5;background-color:var(--gray-light,#e5e5e5)}.van-slider__bar{position:relative;border-radius:inherit;background-color:#1989fa;background-color:var(--blue,#1989fa)}.van-slider__button{width:20px;height:20px;border-radius:50%;box-shadow:0 1px 2px rgba(0,0,0,.5);background-color:#fff;background-color:var(--white,#fff)}.van-slider__button-wrapper{position:absolute;top:50%;right:0;-webkit-transform:translate3d(50%,-50%,0);transform:translate3d(50%,-50%,0)}.van-slider__button-wrapper:after{position:absolute;top:-50%;left:-50%;width:200%;height:200%;content:""}.van-slider--disabled{opacity:.3}
\ No newline at end of file
+@import '../common/index.wxss';.van-slider{position:relative;border-radius:999px;background-color:#e5e5e5;background-color:var(--gray-light,#e5e5e5)}.van-slider:before{position:absolute;top:-8px;right:0;bottom:-8px;left:0;content:""}.van-slider__bar{position:relative;border-radius:inherit;transition:width .2s;background-color:#1989fa;background-color:var(--blue,#1989fa)}.van-slider__button{width:24px;height:24px;border-radius:50%;box-shadow:0 1px 2px rgba(0,0,0,.5);background-color:#fff;background-color:var(--white,#fff)}.van-slider__button-wrapper{position:absolute;top:50%;right:0;-webkit-transform:translate3d(50%,-50%,0);transform:translate3d(50%,-50%,0)}.van-slider--disabled{opacity:.3}
\ No newline at end of file
diff --git a/dist/stepper/index.js b/dist/stepper/index.js
index f67c5b87..10c2770e 100644
--- a/dist/stepper/index.js
+++ b/dist/stepper/index.js
@@ -2,6 +2,11 @@ import { VantComponent } from '../common/component';
 import { addUnit, isDef } from '../common/utils';
 const LONG_PRESS_START_TIME = 600;
 const LONG_PRESS_INTERVAL = 200;
+// add num and avoid float number
+function add(num1, num2) {
+    const cardinal = Math.pow(10, 10);
+    return Math.round((num1 + num2) * cardinal) / cardinal;
+}
 VantComponent({
     field: true,
     classes: ['input-class', 'plus-class', 'minus-class'],
@@ -13,7 +18,10 @@ VantComponent({
         buttonSize: null,
         asyncChange: Boolean,
         disableInput: Boolean,
-        decimalLength: Number,
+        decimalLength: {
+            type: Number,
+            value: null
+        },
         min: {
             type: null,
             value: 1
@@ -105,10 +113,7 @@ VantComponent({
                 return;
             }
             const diff = type === 'minus' ? -this.data.step : +this.data.step;
-            let value = +this.data.value + diff;
-            if (!isDef(this.data.decimalLength)) {
-                value = Math.round(value * 100) / 100;
-            }
+            const value = add(+this.data.value, diff);
             this.triggerInput(this.range(value));
             this.$emit(type);
         },
diff --git a/dist/tabs/index.js b/dist/tabs/index.js
index f58baf1b..74e8e506 100644
--- a/dist/tabs/index.js
+++ b/dist/tabs/index.js
@@ -78,7 +78,7 @@ VantComponent({
         trackStyle: '',
         wrapStyle: '',
         position: '',
-        currentIndex: null,
+        currentIndex: 0,
     },
     watch: {
         swipeThreshold() {
@@ -194,7 +194,7 @@ VantComponent({
         },
         setActiveTab() {
             if (!isDef(this.currentName)) {
-                this.currentName = this.data.active || this.children[0].computedName;
+                this.currentName = this.data.active || (this.children[0] || {}).computedName;
             }
             this.children.forEach((item, index) => {
                 const data = {
diff --git a/lib/action-sheet/index.js b/lib/action-sheet/index.js
index f37fd1b3..c59eb893 100644
--- a/lib/action-sheet/index.js
+++ b/lib/action-sheet/index.js
@@ -6,6 +6,7 @@ component_1.VantComponent({
         show: Boolean,
         title: String,
         cancelText: String,
+        description: String,
         round: {
             type: Boolean,
             value: true
diff --git a/lib/action-sheet/index.wxml b/lib/action-sheet/index.wxml
index c5bbf685..2dcbf4f8 100644
--- a/lib/action-sheet/index.wxml
+++ b/lib/action-sheet/index.wxml
@@ -19,6 +19,9 @@
       bind:click="onClose"
     />
   </view>
+  <view wx:if="{{ description }}" class="van-action-sheet__description">
+    {{ description }}
+  </view>
   <view wx:if="{{ actions && actions.length }}">
     <!-- button外包一层view，防止actions动态变化，导致渲染时button被打散 -->
     <button
diff --git a/lib/action-sheet/index.wxss b/lib/action-sheet/index.wxss
index f88ad2a8..c40c051d 100644
--- a/lib/action-sheet/index.wxss
+++ b/lib/action-sheet/index.wxss
@@ -1 +1 @@
-@import '../common/index.wxss';.van-action-sheet{max-height:90%!important;color:#333;color:var(--text-color,#333)}.van-action-sheet__cancel,.van-action-sheet__item{height:50px;font-size:16px;line-height:50px;text-align:center;background-color:#fff;background-color:var(--white,#fff)}.van-action-sheet__cancel--hover,.van-action-sheet__item--hover{background-color:#f2f3f5;background-color:var(--active-color,#f2f3f5)}.van-action-sheet__cancel{height:60px}.van-action-sheet__cancel:before{display:block;height:10px;content:" ";background-color:#f8f8f8;background-color:var(--background-color,#f8f8f8)}.van-action-sheet__item--disabled{color:#c9c9c9;color:var(--gray,#c9c9c9)}.van-action-sheet__item--disabled.van-action-sheet__item--hover{background-color:#fff;background-color:var(--white,#fff)}.van-action-sheet__subname{margin-left:5px;font-size:12px;color:#7d7e80;color:var(--gray-darker,#7d7e80)}.van-action-sheet__header{font-weight:500;font-size:16px;line-height:44px;text-align:center}.van-action-sheet__close{position:absolute!important;top:0;right:0;padding:0 15px;font-size:18px!important;line-height:inherit!important;color:#999;color:var(--gray-dark,#999)}
\ No newline at end of file
+@import '../common/index.wxss';.van-action-sheet{max-height:90%!important;color:#333;color:var(--text-color,#333)}.van-action-sheet__cancel,.van-action-sheet__item{height:50px;font-size:16px;line-height:50px;text-align:center;background-color:#fff;background-color:var(--white,#fff)}.van-action-sheet__cancel--hover,.van-action-sheet__item--hover{background-color:#f2f3f5;background-color:var(--active-color,#f2f3f5)}.van-action-sheet__cancel{height:60px}.van-action-sheet__cancel:before{display:block;height:10px;content:" ";background-color:#f8f8f8;background-color:var(--background-color,#f8f8f8)}.van-action-sheet__item--disabled{color:#c9c9c9;color:var(--gray,#c9c9c9)}.van-action-sheet__item--disabled.van-action-sheet__item--hover{background-color:#fff;background-color:var(--white,#fff)}.van-action-sheet__subname{margin-left:5px;font-size:12px;color:#7d7e80;color:var(--gray-darker,#7d7e80)}.van-action-sheet__header{font-weight:500;font-size:16px;line-height:44px;text-align:center}.van-action-sheet__description{padding:16px;color:#7d7e80;font-size:14px;line-height:20px;text-align:center}.van-action-sheet__close{position:absolute!important;top:0;right:0;padding:0 15px;font-size:18px!important;line-height:inherit!important;color:#999;color:var(--gray-dark,#999)}
\ No newline at end of file
diff --git a/lib/area/index.js b/lib/area/index.js
index 231c65f2..a2a02029 100644
--- a/lib/area/index.js
+++ b/lib/area/index.js
@@ -13,6 +13,7 @@ var __assign = (this && this.__assign) || function () {
 Object.defineProperty(exports, "__esModule", { value: true });
 var component_1 = require("../common/component");
 var shared_1 = require("../picker/shared");
+var COLUMNSPLACEHOLDERCODE = '000000';
 component_1.VantComponent({
     classes: ['active-class', 'toolbar-class', 'column-class'],
     props: __assign(__assign({}, shared_1.pickerProps), { value: String, areaList: {
@@ -21,10 +22,22 @@ component_1.VantComponent({
         }, columnsNum: {
             type: null,
             value: 3
+        }, columnsPlaceholder: {
+            type: Array,
+            observer: function (val) {
+                this.setData({
+                    typeToColumnsPlaceholder: {
+                        province: val[0] || '',
+                        city: val[1] || '',
+                        county: val[2] || '',
+                    }
+                });
+            }
         } }),
     data: {
         columns: [{ values: [] }, { values: [] }, { values: [] }],
-        displayColumns: [{ values: [] }, { values: [] }, { values: [] }]
+        displayColumns: [{ values: [] }, { values: [] }, { values: [] }],
+        typeToColumnsPlaceholder: {}
     },
     watch: {
         value: function (value) {
@@ -55,21 +68,39 @@ component_1.VantComponent({
             this.emit('cancel', event.detail);
         },
         onConfirm: function (event) {
-            this.emit('confirm', event.detail);
+            var index = event.detail.index;
+            var value = event.detail.value;
+            value = this.parseOutputValues(value);
+            this.emit('confirm', { value: value, index: index });
         },
         emit: function (type, detail) {
             detail.values = detail.value;
             delete detail.value;
             this.$emit(type, detail);
         },
+        // parse output columns data
+        parseOutputValues: function (values) {
+            var columnsPlaceholder = this.data.columnsPlaceholder;
+            return values.map(function (value, index) {
+                if (value === void 0) { value = {}; }
+                value = JSON.parse(JSON.stringify(value));
+                if (!value.code || value.name === columnsPlaceholder[index]) {
+                    value.code = '';
+                    value.name = '';
+                }
+                return value;
+            });
+        },
         onChange: function (event) {
             var _this = this;
             var _a = event.detail, index = _a.index, picker = _a.picker, value = _a.value;
             this.code = value[index].code;
+            var getValues = picker.getValues();
+            getValues = this.parseOutputValues(getValues);
             this.setValues().then(function () {
                 _this.$emit('change', {
                     picker: picker,
-                    values: picker.getValues(),
+                    values: getValues,
                     index: index
                 });
             });
@@ -79,6 +110,7 @@ component_1.VantComponent({
             return (areaList && areaList[type + "_list"]) || {};
         },
         getList: function (type, code) {
+            var typeToColumnsPlaceholder = this.data.typeToColumnsPlaceholder;
             var result = [];
             if (type !== 'province' && !code) {
                 return result;
@@ -95,6 +127,14 @@ component_1.VantComponent({
                 }
                 result = result.filter(function (item) { return item.code.indexOf(code) === 0; });
             }
+            if (typeToColumnsPlaceholder[type] && result.length) {
+                // set columns placeholder
+                var codeFill = type === 'province' ? '' : type === 'city' ? COLUMNSPLACEHOLDERCODE.slice(2, 4) : COLUMNSPLACEHOLDERCODE.slice(4, 6);
+                result.unshift({
+                    code: "" + code + codeFill,
+                    name: typeToColumnsPlaceholder[type]
+                });
+            }
             return result;
         },
         getIndex: function (type, code) {
@@ -115,7 +155,18 @@ component_1.VantComponent({
         setValues: function () {
             var _this = this;
             var county = this.getConfig('county');
-            var code = this.code || Object.keys(county)[0] || '';
+            var code = this.code;
+            if (!code) {
+                if (this.data.columnsPlaceholder.length) {
+                    code = COLUMNSPLACEHOLDERCODE;
+                }
+                else if (Object.keys(county)[0]) {
+                    code = Object.keys(county)[0];
+                }
+                else {
+                    code = '';
+                }
+            }
             var province = this.getList('province');
             var city = this.getList('city', code.slice(0, 2));
             var picker = this.getPicker();
diff --git a/lib/count-down/index.js b/lib/count-down/index.js
new file mode 100644
index 00000000..1db78c8c
--- /dev/null
+++ b/lib/count-down/index.js
@@ -0,0 +1,100 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+var component_1 = require("../common/component");
+var utils_1 = require("./utils");
+function simpleTick(fn) {
+    return setTimeout(fn, 30);
+}
+component_1.VantComponent({
+    props: {
+        useSlot: Boolean,
+        millisecond: Boolean,
+        time: {
+            type: Number,
+            observer: 'reset'
+        },
+        format: {
+            type: String,
+            value: 'HH:mm:ss'
+        },
+        autoStart: {
+            type: Boolean,
+            value: true
+        }
+    },
+    data: {
+        timeData: utils_1.parseTimeData(0),
+        formattedTime: '0'
+    },
+    methods: {
+        // 开始
+        start: function () {
+            if (this.counting) {
+                return;
+            }
+            this.counting = true;
+            this.endTime = Date.now() + this.remain;
+            this.tick();
+        },
+        // 暂停
+        pause: function () {
+            this.counting = false;
+            clearTimeout(this.tid);
+        },
+        // 重置
+        reset: function () {
+            this.pause();
+            this.remain = this.data.time;
+            this.setRemain(this.remain);
+            if (this.data.autoStart) {
+                this.start();
+            }
+        },
+        tick: function () {
+            if (this.data.millisecond) {
+                this.microTick();
+            }
+            else {
+                this.macroTick();
+            }
+        },
+        microTick: function () {
+            var _this = this;
+            this.tid = simpleTick(function () {
+                _this.setRemain(_this.getRemain());
+                if (_this.remain !== 0) {
+                    _this.microTick();
+                }
+            });
+        },
+        macroTick: function () {
+            var _this = this;
+            this.tid = simpleTick(function () {
+                var remain = _this.getRemain();
+                if (!utils_1.isSameSecond(remain, _this.remain) || remain === 0) {
+                    _this.setRemain(remain);
+                }
+                if (_this.remain !== 0) {
+                    _this.macroTick();
+                }
+            });
+        },
+        getRemain: function () {
+            return Math.max(this.endTime - Date.now(), 0);
+        },
+        setRemain: function (remain) {
+            this.remain = remain;
+            var timeData = utils_1.parseTimeData(remain);
+            if (this.data.useSlot) {
+                this.$emit('change', timeData);
+            }
+            this.setData({
+                formattedTime: utils_1.parseFormat(this.data.format, timeData)
+            });
+            if (remain === 0) {
+                this.pause();
+                this.$emit('finish');
+            }
+        }
+    }
+});
diff --git a/lib/count-down/index.json b/lib/count-down/index.json
new file mode 100644
index 00000000..467ce294
--- /dev/null
+++ b/lib/count-down/index.json
@@ -0,0 +1,3 @@
+{
+  "component": true
+}
diff --git a/lib/count-down/index.wxml b/lib/count-down/index.wxml
new file mode 100644
index 00000000..e206e167
--- /dev/null
+++ b/lib/count-down/index.wxml
@@ -0,0 +1,4 @@
+<view class="van-count-down">
+  <slot wx:if="{{ useSlot }}"/>
+  <block wx:else>{{ formattedTime }}</block>
+</view>
diff --git a/lib/count-down/index.wxss b/lib/count-down/index.wxss
new file mode 100644
index 00000000..275d5739
--- /dev/null
+++ b/lib/count-down/index.wxss
@@ -0,0 +1 @@
+@import '../common/index.wxss';.van-count-down{color:#333;font-size:14px;line-height:20px}
\ No newline at end of file
diff --git a/lib/count-down/utils.js b/lib/count-down/utils.js
new file mode 100644
index 00000000..19195e2b
--- /dev/null
+++ b/lib/count-down/utils.js
@@ -0,0 +1,63 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+function padZero(num, targetLength) {
+    if (targetLength === void 0) { targetLength = 2; }
+    var str = num + '';
+    while (str.length < targetLength) {
+        str = '0' + str;
+    }
+    return str;
+}
+var SECOND = 1000;
+var MINUTE = 60 * SECOND;
+var HOUR = 60 * MINUTE;
+var DAY = 24 * HOUR;
+function parseTimeData(time) {
+    var days = Math.floor(time / DAY);
+    var hours = Math.floor((time % DAY) / HOUR);
+    var minutes = Math.floor((time % HOUR) / MINUTE);
+    var seconds = Math.floor((time % MINUTE) / SECOND);
+    var milliseconds = Math.floor(time % SECOND);
+    return {
+        days: days,
+        hours: hours,
+        minutes: minutes,
+        seconds: seconds,
+        milliseconds: milliseconds
+    };
+}
+exports.parseTimeData = parseTimeData;
+function parseFormat(format, timeData) {
+    var days = timeData.days;
+    var hours = timeData.hours, minutes = timeData.minutes, seconds = timeData.seconds, milliseconds = timeData.milliseconds;
+    if (format.indexOf('DD') === -1) {
+        hours += days * 24;
+    }
+    else {
+        format = format.replace('DD', padZero(days));
+    }
+    if (format.indexOf('HH') === -1) {
+        minutes += hours * 60;
+    }
+    else {
+        format = format.replace('HH', padZero(hours));
+    }
+    if (format.indexOf('mm') === -1) {
+        seconds += minutes * 60;
+    }
+    else {
+        format = format.replace('mm', padZero(minutes));
+    }
+    if (format.indexOf('ss') === -1) {
+        milliseconds += seconds * 1000;
+    }
+    else {
+        format = format.replace('ss', padZero(seconds));
+    }
+    return format.replace('SSS', padZero(milliseconds, 3));
+}
+exports.parseFormat = parseFormat;
+function isSameSecond(time1, time2) {
+    return Math.floor(time1 / 1000) === Math.floor(time2 / 1000);
+}
+exports.isSameSecond = isSameSecond;
diff --git a/lib/dialog/dialog.js b/lib/dialog/dialog.js
index ff7ac167..e3e3323b 100644
--- a/lib/dialog/dialog.js
+++ b/lib/dialog/dialog.js
@@ -35,15 +35,17 @@ var Dialog = function (options) {
 Dialog.defaultOptions = {
     show: true,
     title: '',
+    width: null,
     message: '',
     zIndex: 100,
     overlay: true,
-    className: '',
-    customStyle: '',
-    asyncClose: false,
-    messageAlign: '',
-    transition: 'scale',
     selector: '#van-dialog',
+    className: '',
+    asyncClose: false,
+    transition: 'scale',
+    customStyle: '',
+    messageAlign: '',
+    overlayStyle: '',
     confirmButtonText: '确认',
     cancelButtonText: '取消',
     showConfirmButton: true,
diff --git a/lib/dialog/index.js b/lib/dialog/index.js
index 838b7b19..6748bc7a 100644
--- a/lib/dialog/index.js
+++ b/lib/dialog/index.js
@@ -3,6 +3,7 @@ Object.defineProperty(exports, "__esModule", { value: true });
 var component_1 = require("../common/component");
 var button_1 = require("../mixins/button");
 var open_type_1 = require("../mixins/open-type");
+var utils_1 = require("../common/utils");
 var color_1 = require("../common/color");
 component_1.VantComponent({
     mixins: [button_1.button, open_type_1.openType],
@@ -15,10 +16,15 @@ component_1.VantComponent({
         customStyle: String,
         asyncClose: Boolean,
         messageAlign: String,
+        overlayStyle: String,
         useTitleSlot: Boolean,
         showCancelButton: Boolean,
         closeOnClickOverlay: Boolean,
         confirmButtonOpenType: String,
+        width: {
+            type: null,
+            observer: 'setWidthWithUnit'
+        },
         zIndex: {
             type: Number,
             value: 2000
@@ -106,6 +112,11 @@ component_1.VantComponent({
             if (callback) {
                 callback(this);
             }
+        },
+        setWidthWithUnit: function (val) {
+            this.setData({
+                widthWithUnit: utils_1.addUnit(val)
+            });
         }
     }
 });
diff --git a/lib/dialog/index.wxml b/lib/dialog/index.wxml
index 1f02b3d8..854e8a14 100644
--- a/lib/dialog/index.wxml
+++ b/lib/dialog/index.wxml
@@ -2,9 +2,10 @@
   show="{{ show }}"
   z-index="{{ zIndex }}"
   overlay="{{ overlay }}"
-  custom-class="van-dialog {{ className }}"
   transition="{{ transition }}"
-  custom-style="{{ customStyle }}"
+  custom-class="van-dialog {{ className }}"
+  custom-style="{{ widthWithUnit ? 'width: ' + widthWithUnit + ';' : '' }}{{ customStyle }}"
+  overlay-style="{{ overlayStyle }}"
   close-on-click-overlay="{{ closeOnClickOverlay }}"
   bind:close="onClickOverlay"
 >
diff --git a/lib/dialog/index.wxss b/lib/dialog/index.wxss
index c7a331d4..869c5c35 100644
--- a/lib/dialog/index.wxss
+++ b/lib/dialog/index.wxss
@@ -1 +1 @@
-@import '../common/index.wxss';.van-dialog{top:45%!important;width:85%;overflow:hidden;font-size:16px;border-radius:4px;background-color:#fff;background-color:var(--white,#fff)}.van-dialog__header{padding-top:25px;font-weight:500;line-height:24px;text-align:center}.van-dialog__header--isolated{padding:25px 0}.van-dialog__message{max-height:60vh;padding:25px;overflow-y:auto;font-size:14px;line-height:20px;text-align:center;-webkit-overflow-scrolling:touch}.van-dialog__message-text{word-wrap:break-word}.van-dialog__message--has-title{padding-top:12px;color:#7d7e80;color:var(--gray-darker,#7d7e80)}.van-dialog__message--left{text-align:left}.van-dialog__message--right{text-align:right}.van-dialog__footer{display:-webkit-flex;display:flex}.van-dialog__button{-webkit-flex:1;flex:1}.van-dialog__cancel,.van-dialog__confirm{border:0!important}.van-dialog-bounce-enter{-webkit-transform:translate3d(-50%,-50%,0) scale(.7);transform:translate3d(-50%,-50%,0) scale(.7);opacity:0}.van-dialog-bounce-leave-active{-webkit-transform:translate3d(-50%,-50%,0) scale(.9);transform:translate3d(-50%,-50%,0) scale(.9);opacity:0}
\ No newline at end of file
+@import '../common/index.wxss';.van-dialog{top:45%!important;width:320px;overflow:hidden;font-size:16px;border-radius:4px;background-color:#fff;background-color:var(--white,#fff)}@media (max-width:321px){.van-dialog{width:90%}}.van-dialog__header{padding-top:25px;font-weight:500;line-height:24px;text-align:center}.van-dialog__header--isolated{padding:25px 0}.van-dialog__message{max-height:60vh;padding:25px;overflow-y:auto;font-size:14px;line-height:20px;text-align:center;-webkit-overflow-scrolling:touch}.van-dialog__message-text{word-wrap:break-word}.van-dialog__message--has-title{padding-top:12px;color:#7d7e80;color:var(--gray-darker,#7d7e80)}.van-dialog__message--left{text-align:left}.van-dialog__message--right{text-align:right}.van-dialog__footer{display:-webkit-flex;display:flex}.van-dialog__button{-webkit-flex:1;flex:1}.van-dialog__cancel,.van-dialog__confirm{border:0!important}.van-dialog-bounce-enter{-webkit-transform:translate3d(-50%,-50%,0) scale(.7);transform:translate3d(-50%,-50%,0) scale(.7);opacity:0}.van-dialog-bounce-leave-active{-webkit-transform:translate3d(-50%,-50%,0) scale(.9);transform:translate3d(-50%,-50%,0) scale(.9);opacity:0}
\ No newline at end of file
diff --git a/lib/loading/index.js b/lib/loading/index.js
index 50b2c5de..efbf9d2c 100644
--- a/lib/loading/index.js
+++ b/lib/loading/index.js
@@ -15,16 +15,27 @@ component_1.VantComponent({
         color: {
             type: String,
             value: '#c9c9c9'
-        }
+        },
+        textSize: {
+            type: String,
+            observer: 'setTextSizeWithUnit'
+        },
+        vertical: Boolean
     },
     data: {
-        sizeWithUnit: '30px'
+        sizeWithUnit: '30px',
+        textSizeWithUnit: '14px'
     },
     methods: {
         setSizeWithUnit: function (size) {
             this.setData({
                 sizeWithUnit: utils_1.addUnit(size)
             });
+        },
+        setTextSizeWithUnit: function (size) {
+            this.set({
+                textSizeWithUnit: utils_1.addUnit(size)
+            });
         }
     }
 });
diff --git a/lib/loading/index.wxml b/lib/loading/index.wxml
index ff329466..88b0148f 100644
--- a/lib/loading/index.wxml
+++ b/lib/loading/index.wxml
@@ -1,16 +1,24 @@
-<view
-  class="van-loading custom-class"
-  style="width: {{ sizeWithUnit }}; height: {{ sizeWithUnit }}"
->
+<view class="van-loading {{vertical ? 'van-loading--vertical' : ''}}">
   <view
-    class="van-loading__spinner van-loading__spinner--{{ type }}"
-    style="color: {{ color }};"
+    class="van-loading__wrapper custom-class"
+    style="width: {{ sizeWithUnit }}; height: {{ sizeWithUnit }}"
   >
     <view
-      wx:if="{{ type === 'spinner' }}"
-      wx:for="item in 12"
-      wx:key="index"
-      class="van-loading__dot"
-    />
+      class="van-loading__spinner van-loading__spinner--{{ type }}"
+      style="color: {{ color }};"
+    >
+      <view
+        wx:if="{{ type === 'spinner' }}"
+        wx:for="item in 12"
+        wx:key="index"
+        class="van-loading__dot"
+      />
+    </view>
+  </view>
+  <view 
+    style="font-size: {{textSizeWithUnit}};" 
+    class="van-loading__text {{vertical ? 'van-loading__text--vertical' : ''}}"
+  >
+    <slot />
   </view>
 </view>
\ No newline at end of file
diff --git a/lib/loading/index.wxss b/lib/loading/index.wxss
index 43ffdafa..64ceff23 100644
--- a/lib/loading/index.wxss
+++ b/lib/loading/index.wxss
@@ -1 +1 @@
-@import '../common/index.wxss';.van-loading{z-index:0;line-height:0;vertical-align:middle}.van-loading,.van-loading__spinner{position:relative;display:inline-block}.van-loading__spinner{z-index:-1;box-sizing:border-box;width:100%;height:100%;-webkit-animation:van-rotate .8s linear infinite;animation:van-rotate .8s linear infinite}.van-loading__spinner--spinner{-webkit-animation-timing-function:steps(12);animation-timing-function:steps(12)}.van-loading__spinner--circular{border:1px solid transparent;border-top-color:initial;border-radius:100%}.van-loading__dot{position:absolute;top:0;left:0;width:100%;height:100%}.van-loading__dot:before{display:block;width:2px;height:25%;margin:0 auto;background-color:currentColor;border-radius:40%;content:" "}.van-loading__dot:first-of-type{-webkit-transform:rotate(30deg);transform:rotate(30deg);opacity:1}.van-loading__dot:nth-of-type(2){-webkit-transform:rotate(60deg);transform:rotate(60deg);opacity:.9375}.van-loading__dot:nth-of-type(3){-webkit-transform:rotate(90deg);transform:rotate(90deg);opacity:.875}.van-loading__dot:nth-of-type(4){-webkit-transform:rotate(120deg);transform:rotate(120deg);opacity:.8125}.van-loading__dot:nth-of-type(5){-webkit-transform:rotate(150deg);transform:rotate(150deg);opacity:.75}.van-loading__dot:nth-of-type(6){-webkit-transform:rotate(180deg);transform:rotate(180deg);opacity:.6875}.van-loading__dot:nth-of-type(7){-webkit-transform:rotate(210deg);transform:rotate(210deg);opacity:.625}.van-loading__dot:nth-of-type(8){-webkit-transform:rotate(240deg);transform:rotate(240deg);opacity:.5625}.van-loading__dot:nth-of-type(9){-webkit-transform:rotate(270deg);transform:rotate(270deg);opacity:.5}.van-loading__dot:nth-of-type(10){-webkit-transform:rotate(300deg);transform:rotate(300deg);opacity:.4375}.van-loading__dot:nth-of-type(11){-webkit-transform:rotate(330deg);transform:rotate(330deg);opacity:.375}.van-loading__dot:nth-of-type(12){-webkit-transform:rotate(1turn);transform:rotate(1turn);opacity:.3125}@-webkit-keyframes van-rotate{0%{-webkit-transform:rotate(0deg);transform:rotate(0deg)}to{-webkit-transform:rotate(1turn);transform:rotate(1turn)}}@keyframes van-rotate{0%{-webkit-transform:rotate(0deg);transform:rotate(0deg)}to{-webkit-transform:rotate(1turn);transform:rotate(1turn)}}
\ No newline at end of file
+@import '../common/index.wxss';.van-loading{display:-webkit-inline-flex;display:inline-flex;-webkit-align-items:center;align-items:center;-webkit-justify-content:center;justify-content:center}.van-loading__wrapper{position:relative;z-index:0;display:inline-block;line-height:0}.van-loading--vertical{-webkit-flex-direction:column;flex-direction:column}.van-loading__spinner{position:relative;z-index:-1;display:inline-block;box-sizing:border-box;width:100%;height:100%;-webkit-animation:van-rotate .8s linear infinite;animation:van-rotate .8s linear infinite}.van-loading__spinner--spinner{-webkit-animation-timing-function:steps(12);animation-timing-function:steps(12)}.van-loading__spinner--circular{border:1px solid transparent;border-top-color:initial;border-radius:100%}.van-loading__text{margin-left:8px;color:#969799}.van-loading__text--vertical{margin:8px 0 0}.van-loading__dot{position:absolute;top:0;left:0;width:100%;height:100%}.van-loading__dot:before{display:block;width:2px;height:25%;margin:0 auto;background-color:currentColor;border-radius:40%;content:" "}.van-loading__dot:first-of-type{-webkit-transform:rotate(30deg);transform:rotate(30deg);opacity:1}.van-loading__dot:nth-of-type(2){-webkit-transform:rotate(60deg);transform:rotate(60deg);opacity:.9375}.van-loading__dot:nth-of-type(3){-webkit-transform:rotate(90deg);transform:rotate(90deg);opacity:.875}.van-loading__dot:nth-of-type(4){-webkit-transform:rotate(120deg);transform:rotate(120deg);opacity:.8125}.van-loading__dot:nth-of-type(5){-webkit-transform:rotate(150deg);transform:rotate(150deg);opacity:.75}.van-loading__dot:nth-of-type(6){-webkit-transform:rotate(180deg);transform:rotate(180deg);opacity:.6875}.van-loading__dot:nth-of-type(7){-webkit-transform:rotate(210deg);transform:rotate(210deg);opacity:.625}.van-loading__dot:nth-of-type(8){-webkit-transform:rotate(240deg);transform:rotate(240deg);opacity:.5625}.van-loading__dot:nth-of-type(9){-webkit-transform:rotate(270deg);transform:rotate(270deg);opacity:.5}.van-loading__dot:nth-of-type(10){-webkit-transform:rotate(300deg);transform:rotate(300deg);opacity:.4375}.van-loading__dot:nth-of-type(11){-webkit-transform:rotate(330deg);transform:rotate(330deg);opacity:.375}.van-loading__dot:nth-of-type(12){-webkit-transform:rotate(1turn);transform:rotate(1turn);opacity:.3125}@-webkit-keyframes van-rotate{0%{-webkit-transform:rotate(0deg);transform:rotate(0deg)}to{-webkit-transform:rotate(1turn);transform:rotate(1turn)}}@keyframes van-rotate{0%{-webkit-transform:rotate(0deg);transform:rotate(0deg)}to{-webkit-transform:rotate(1turn);transform:rotate(1turn)}}
\ No newline at end of file
diff --git a/lib/mixins/transition.js b/lib/mixins/transition.js
index 1f69ce68..7c64a994 100644
--- a/lib/mixins/transition.js
+++ b/lib/mixins/transition.js
@@ -41,12 +41,7 @@ exports.transition = function (showDefaultValue) {
         },
         methods: {
             observeShow: function (value) {
-                if (value) {
-                    this.enter();
-                }
-                else {
-                    this.leave();
-                }
+                value ? this.enter() : this.leave();
             },
             enter: function () {
                 var _this = this;
@@ -54,10 +49,12 @@ exports.transition = function (showDefaultValue) {
                 var classNames = getClassNames(name);
                 var currentDuration = utils_1.isObj(duration) ? duration.enter : duration;
                 this.status = 'enter';
+                this.$emit('before-enter');
                 Promise.resolve()
                     .then(nextTick)
                     .then(function () {
                     _this.checkStatus('enter');
+                    _this.$emit('enter');
                     _this.setData({
                         inited: true,
                         display: true,
@@ -68,6 +65,7 @@ exports.transition = function (showDefaultValue) {
                     .then(nextTick)
                     .then(function () {
                     _this.checkStatus('enter');
+                    _this.transitionEnded = false;
                     _this.setData({
                         classes: classNames['enter-to']
                     });
@@ -76,23 +74,29 @@ exports.transition = function (showDefaultValue) {
             },
             leave: function () {
                 var _this = this;
+                if (!this.data.display) {
+                    return;
+                }
                 var _a = this.data, duration = _a.duration, name = _a.name;
                 var classNames = getClassNames(name);
                 var currentDuration = utils_1.isObj(duration) ? duration.leave : duration;
                 this.status = 'leave';
+                this.$emit('before-leave');
                 Promise.resolve()
                     .then(nextTick)
                     .then(function () {
                     _this.checkStatus('leave');
+                    _this.$emit('leave');
                     _this.setData({
                         classes: classNames.leave,
                         currentDuration: currentDuration
                     });
                 })
-                    .then(function () { return setTimeout(function () { return _this.onTransitionEnd(); }, currentDuration); })
                     .then(nextTick)
                     .then(function () {
                     _this.checkStatus('leave');
+                    _this.transitionEnded = false;
+                    setTimeout(function () { return _this.onTransitionEnd(); }, currentDuration);
                     _this.setData({
                         classes: classNames['leave-to']
                     });
@@ -105,9 +109,14 @@ exports.transition = function (showDefaultValue) {
                 }
             },
             onTransitionEnd: function () {
-                if (!this.data.show) {
-                    this.set({ display: false });
-                    this.$emit('transitionend');
+                if (this.transitionEnded) {
+                    return;
+                }
+                this.transitionEnded = true;
+                this.$emit("after-" + this.status);
+                var _a = this.data, show = _a.show, display = _a.display;
+                if (!show && display) {
+                    this.setData({ display: false });
                 }
             }
         }
diff --git a/lib/nav-bar/index.js b/lib/nav-bar/index.js
index 37226c7f..fc1b0806 100644
--- a/lib/nav-bar/index.js
+++ b/lib/nav-bar/index.js
@@ -22,6 +22,13 @@ component_1.VantComponent({
             value: true
         },
     },
+    data: {
+        statusBarHeight: 0
+    },
+    created: function () {
+        var statusBarHeight = wx.getSystemInfoSync().statusBarHeight;
+        this.setData({ statusBarHeight: statusBarHeight });
+    },
     methods: {
         onClickLeft: function () {
             this.$emit('click-left');
diff --git a/lib/nav-bar/index.wxml b/lib/nav-bar/index.wxml
index b3690aeb..9ed4446f 100644
--- a/lib/nav-bar/index.wxml
+++ b/lib/nav-bar/index.wxml
@@ -1,8 +1,8 @@
 <wxs src="../wxs/utils.wxs" module="utils" />
 
 <view
-  class="{{ utils.bem('nav-bar', { fixed, safe: safeAreaInsetTop }) }} custom-class {{ border ? 'van-hairline--bottom' : '' }}"
-  style="z-index: {{ zIndex }};"
+  class="{{ utils.bem('nav-bar', { fixed }) }} custom-class {{ border ? 'van-hairline--bottom' : '' }}"
+  style="z-index: {{ zIndex }}; padding-top: {{ safeAreaInsetTop ? statusBarHeight : 0 }}px;"
 >
   <view class="van-nav-bar__left" bind:tap="onClickLeft">
     <block wx:if="{{ leftArrow || leftText }}">
diff --git a/lib/nav-bar/index.wxss b/lib/nav-bar/index.wxss
index b3c344a5..1ba28ea7 100644
--- a/lib/nav-bar/index.wxss
+++ b/lib/nav-bar/index.wxss
@@ -1 +1 @@
-@import '../common/index.wxss';.van-nav-bar{position:relative;text-align:center;-webkit-user-select:none;user-select:none;height:44px;height:var(--nav-bar-height,44px);line-height:44px;line-height:var(--nav-bar-height,44px);background-color:#fff;background-color:var(--white,#fff)}.van-nav-bar--safe{padding-top:env(safe-area-inset-top)}.van-nav-bar__text{display:inline-block;margin:0 -15px;padding:0 15px;vertical-align:middle;color:#1989fa;color:var(--blue,#1989fa)}.van-nav-bar__text--hover{background-color:#f2f3f5;background-color:var(--active-color,#f2f3f5)}.van-nav-bar__arrow{vertical-align:middle;color:#1989fa;color:var(--blue,#1989fa)}.van-nav-bar__arrow+.van-nav-bar__text{margin-left:-20px;padding-left:25px}.van-nav-bar--fixed{position:fixed;top:0;left:0;width:100%}.van-nav-bar__title{max-width:60%;margin:0 auto;font-weight:500;font-size:16px}.van-nav-bar__left,.van-nav-bar__right{position:absolute;bottom:0;font-size:14px}.van-nav-bar__left{left:15px}.van-nav-bar__right{right:15px}
\ No newline at end of file
+@import '../common/index.wxss';.van-nav-bar{position:relative;text-align:center;-webkit-user-select:none;user-select:none;height:44px;height:var(--nav-bar-height,44px);line-height:44px;line-height:var(--nav-bar-height,44px);background-color:#fff;background-color:var(--white,#fff)}.van-nav-bar__text{display:inline-block;margin:0 -15px;padding:0 15px;vertical-align:middle;color:#1989fa;color:var(--blue,#1989fa)}.van-nav-bar__text--hover{background-color:#f2f3f5;background-color:var(--active-color,#f2f3f5)}.van-nav-bar__arrow{vertical-align:middle;color:#1989fa;color:var(--blue,#1989fa)}.van-nav-bar__arrow+.van-nav-bar__text{margin-left:-20px;padding-left:25px}.van-nav-bar--fixed{position:fixed;top:0;left:0;width:100%}.van-nav-bar__title{max-width:60%;margin:0 auto;font-weight:500;font-size:16px}.van-nav-bar__left,.van-nav-bar__right{position:absolute;bottom:0;font-size:14px}.van-nav-bar__left{left:15px}.van-nav-bar__right{right:15px}
\ No newline at end of file
diff --git a/lib/rate/index.wxss b/lib/rate/index.wxss
index acc13946..4538752e 100644
--- a/lib/rate/index.wxss
+++ b/lib/rate/index.wxss
@@ -1 +1 @@
-@import '../common/index.wxss';.van-rate{display:inline-block;-webkit-user-select:none;user-select:none}.van-rate__item{position:relative;display:inline-block;padding:0 2px;padding:0 var(--rate-horizontal-padding,2px)}.van-rate__icon{display:block;height:1em}.van-rate__icon--half{position:absolute;top:0;width:.5em;overflow:hidden;left:2px;left:var(--rate-horizontal-padding,2px)}
\ No newline at end of file
+@import '../common/index.wxss';.van-rate{display:-webkit-inline-flex;display:inline-flex;-webkit-user-select:none;user-select:none}.van-rate__item{position:relative;padding:0 2px;padding:0 var(--rate-horizontal-padding,2px)}.van-rate__icon{display:block;height:1em}.van-rate__icon--half{position:absolute;top:0;width:.5em;overflow:hidden;left:2px;left:var(--rate-horizontal-padding,2px)}
\ No newline at end of file
diff --git a/lib/slider/index.js b/lib/slider/index.js
index a879daba..d22b9d62 100644
--- a/lib/slider/index.js
+++ b/lib/slider/index.js
@@ -86,7 +86,7 @@ component_1.VantComponent({
             var width = ((value - min) * 100) / this.getRange() + "%";
             this.setData({
                 value: value,
-                barStyle: "width: " + width + "; height: " + utils_1.addUnit(barHeight) + ";"
+                barStyle: "\n          width: " + width + ";\n          height: " + utils_1.addUnit(barHeight) + ";\n          " + (drag ? 'transition: none;' : '') + "\n        ",
             });
             if (drag) {
                 this.$emit('drag', { value: value });
diff --git a/lib/slider/index.wxss b/lib/slider/index.wxss
index 28d5bff1..85681030 100644
--- a/lib/slider/index.wxss
+++ b/lib/slider/index.wxss
@@ -1 +1 @@
-@import '../common/index.wxss';.van-slider{position:relative;border-radius:999px;background-color:#e5e5e5;background-color:var(--gray-light,#e5e5e5)}.van-slider__bar{position:relative;border-radius:inherit;background-color:#1989fa;background-color:var(--blue,#1989fa)}.van-slider__button{width:20px;height:20px;border-radius:50%;box-shadow:0 1px 2px rgba(0,0,0,.5);background-color:#fff;background-color:var(--white,#fff)}.van-slider__button-wrapper{position:absolute;top:50%;right:0;-webkit-transform:translate3d(50%,-50%,0);transform:translate3d(50%,-50%,0)}.van-slider__button-wrapper:after{position:absolute;top:-50%;left:-50%;width:200%;height:200%;content:""}.van-slider--disabled{opacity:.3}
\ No newline at end of file
+@import '../common/index.wxss';.van-slider{position:relative;border-radius:999px;background-color:#e5e5e5;background-color:var(--gray-light,#e5e5e5)}.van-slider:before{position:absolute;top:-8px;right:0;bottom:-8px;left:0;content:""}.van-slider__bar{position:relative;border-radius:inherit;transition:width .2s;background-color:#1989fa;background-color:var(--blue,#1989fa)}.van-slider__button{width:24px;height:24px;border-radius:50%;box-shadow:0 1px 2px rgba(0,0,0,.5);background-color:#fff;background-color:var(--white,#fff)}.van-slider__button-wrapper{position:absolute;top:50%;right:0;-webkit-transform:translate3d(50%,-50%,0);transform:translate3d(50%,-50%,0)}.van-slider--disabled{opacity:.3}
\ No newline at end of file
diff --git a/lib/stepper/index.js b/lib/stepper/index.js
index c9e86603..c0c58bb4 100644
--- a/lib/stepper/index.js
+++ b/lib/stepper/index.js
@@ -4,6 +4,11 @@ var component_1 = require("../common/component");
 var utils_1 = require("../common/utils");
 var LONG_PRESS_START_TIME = 600;
 var LONG_PRESS_INTERVAL = 200;
+// add num and avoid float number
+function add(num1, num2) {
+    var cardinal = Math.pow(10, 10);
+    return Math.round((num1 + num2) * cardinal) / cardinal;
+}
 component_1.VantComponent({
     field: true,
     classes: ['input-class', 'plus-class', 'minus-class'],
@@ -15,7 +20,10 @@ component_1.VantComponent({
         buttonSize: null,
         asyncChange: Boolean,
         disableInput: Boolean,
-        decimalLength: Number,
+        decimalLength: {
+            type: Number,
+            value: null
+        },
         min: {
             type: null,
             value: 1
@@ -107,10 +115,7 @@ component_1.VantComponent({
                 return;
             }
             var diff = type === 'minus' ? -this.data.step : +this.data.step;
-            var value = +this.data.value + diff;
-            if (!utils_1.isDef(this.data.decimalLength)) {
-                value = Math.round(value * 100) / 100;
-            }
+            var value = add(+this.data.value, diff);
             this.triggerInput(this.range(value));
             this.$emit(type);
         },
diff --git a/lib/tabs/index.js b/lib/tabs/index.js
index 91148226..45ddd6b0 100644
--- a/lib/tabs/index.js
+++ b/lib/tabs/index.js
@@ -80,7 +80,7 @@ component_1.VantComponent({
         trackStyle: '',
         wrapStyle: '',
         position: '',
-        currentIndex: null,
+        currentIndex: 0,
     },
     watch: {
         swipeThreshold: function () {
@@ -187,7 +187,7 @@ component_1.VantComponent({
         setActiveTab: function () {
             var _this = this;
             if (!utils_1.isDef(this.currentName)) {
-                this.currentName = this.data.active || this.children[0].computedName;
+                this.currentName = this.data.active || (this.children[0] || {}).computedName;
             }
             this.children.forEach(function (item, index) {
                 var data = {