<!- 子组件wxml -->
<view class="child">
    <view class="child_item {{item.isActive===true?'active':''}}" 
     wx:for="test_data" 
     wx:key="id" 
     bindtap="handleTap"
     data-index = {{index}}
    >{{item.name}}</view>
</view>

 绑定点击事件， 子组件触发父组件的自定义事件 this.triggerEvent("事件名",参数）向父组件传递参数

//子组件js
Component({
    properties: {
        test_data:{
           type:Array,
           value:[]
        }
    },
    methods:{
       handleTap(e) {
          const index = e.currentTarget.dataset.index;
          this.triggerEvent("handlefatherEvent",index);
       }
    }
})

<!-- 父组件wxml -->
<child test_data="{{testData}}" bindhandleFatherEvent="handleFatherEvent">
</child>

 父组件绑定自定义事件，接收子组件传递数据

//父组件js
Page({
    data:{
       testData:[
          {id:0,apple,isActive:true},
          {id:1,banana,isActive:false},
          {id:2,grape,isActive:false}
       ]
    },

    handleFatherEvent(e) {
       const index = e.detail;
       let data = this.data.testData;
       data.forEach(
              (v,i)=>i===index? v.isActive=true:v.isActive=false)
       this.setData({testData});
    }
})