点第一次失去焦点，点第二次input才被清空

<view class='searchCon'>
<input type='text' placeholder='搜一搜这是什么垃圾?' value="{{inputVal}}" bindinput='searchInput' bindconfirm="seachBtn"  placeholder-class="placeholderClass" focus='{{isfocus}}' />
<view class='closeBtn' bindtap='deleteBtn'><image src="../../imgs/close.png"></image></view>

// 搜索回删
deleteBtn(){
this.setData({
  isfocus: false,
},()=>{
  this.setData({
    inputVal:''
  })
}) 
},