docs(Search): fix demo problem (#2458)

* docs(Search): fix demo problem

* docs(Search): add demo script

* docs(Search): adjust docs

example/pages/search/index.js

@@ -11,7 +11,16 @@ Page({
     });
   },
 
-  onSearch(event) {
+  onSearch() {
+    if (this.data.value) {
+      wx.showToast({
+        title: '搜索：' + this.data.value,
+        icon: 'none'
+      });
+    }
+  },
+
+  onClick() {
     if (this.data.value) {
       wx.showToast({
         title: '搜索：' + this.data.value,

example/pages/search/index.wxml

@@ -29,6 +29,6 @@
     label="地址"
     shape="round"
   >
-    <view slot="action" bind:tap="onSearch">搜索</view>
+    <view slot="action" bind:tap="onClick">搜索</view>
   </van-search>
 </demo-block>

packages/search/README.md

@@ -43,12 +43,35 @@
   value="{{ value }}"
   placeholder="请输入搜索关键词"
   use-action-slot
+  bind:change="onChange"
   bind:search="onSearch"
 >
-  <view slot="action" bind:tap="onSearch">搜索</view>
+  <view slot="action" bind:tap="onClick">搜索</view>
 </van-search>
 ```
 
+```javascript
+Page({
+  data: {
+    value: ''
+  },
+
+  onChange(e) {
+    this.setData({
+      value: e.detail
+    });
+  },
+
+  onSearch() {
+    Toast('搜索' + this.data.value);
+  },
+
+  onClick() {
+    Toast('搜索' + this.data.value);
+  },
+});
+```
+
 ## API
 
 ### Props