Folding panel

<! - accordion -> 
  < View WX: for = "{} {} produceList" WX: Key = "ID" > 
    < View class = "Horizontal BETWEEN" Data-index = "index {} {}" bindtap = 'changeToggle' > 
      < View class = "" > fold strip left SUMMARY </ View > 
      < View class = "Horizontal" > fold strip to the right content < text class ? = "{{selectedFlag [index] 'Triangle-up': 'Triangle-Down'}} " > </text></view>
    </View > 
    < View class = '' hidden = "{{selectedFlag [index]}!}" > 
      <-! content folding display -> 
    </ View > 
  </ View >

.triangle-down{
  width: 0;
  height: 0;
  border-width: 8px 4px 0;
  border-style: solid;
  border-color:#b2b2b2 transparent transparent;
  margin: 5rpx 0 0 10rpx;
}
.triangle-up{
  width:0;
  height:0;
  border-width:0 4px 8px;
  border-style:solid;
  border-color:transparent transparent #b2b2b2;
  margin: 5rpx 0 0 10rpx;
}

// default false, the state changes to modify the target value corresponding to a state index 
const foldStatus = [ to false , to false , to false , to false , to false , to false , to false , to false , to false , to false , to false , to false , to false , to false , to false ]; / / a 15 data 



// expand a collapsed selection   
  changeToggle: function (E) {
     var index = e.currentTarget.dataset.index;
     IF ( the this.data.selectedFlag[index]) {
      this.data.selectedFlag[index] = false;
    } else {
      this.data.selectedFlag[index] = true;
    }
    this.setData({
      selectedFlag: this.data.selectedFlag
    })
  },