[new feature] Tabbar: add border prop (#1649)

packages/tabbar/README.md

@@ -118,6 +118,7 @@ Page({
 | active | 当前选中标签的索引 | `Number` | - |
 | active-color | 选中标签的颜色 | `String` | `#1989fa` |
 | fixed | 是否固定在底部 | `Boolean` | `true` |
+| border | 是否展示外边框 | `Boolean` | `true` |
 | z-index | 元素 z-index | `Number` | `1` |
 | safe-area-inset-bottom | 是否为iPhoneX留出底部安全距离 | `Boolean` | `true` |
 

packages/tabbar/index.ts

@@ -26,6 +26,10 @@ VantComponent({
       type: Boolean,
       value: true
     },
+    border: {
+      type: Boolean,
+      value: true
+    },
     zIndex: {
       type: Number,
       value: 1

packages/tabbar/index.wxml

@@ -1,7 +1,7 @@
 <wxs src="../wxs/utils.wxs" module="utils" />
 
 <view
-  class="custom-class van-hairline--top-bottom {{ utils.bem('tabbar', { fixed, safe: isIPhoneX && safeAreaInsetBottom }) }}"
+  class="custom-class {{ border ? 'van-hairline--top-bottom' : '' }} {{ utils.bem('tabbar', { fixed, safe: isIPhoneX && safeAreaInsetBottom }) }}"
   style="{{ zIndex ? 'z-index: ' + zIndex : '' }}"
 >
   <slot />