微信小程序获取复选框全选，反选选中的值

wxml文件

<view class="tr">
    <view class="th">
      <checkbox  bindtap="selectall" />全选
    </view>
      <view class="th">id</view>
      <view class="th">名称</view>
</view>

<checkbox-group bindchange="checkboxchange">
    <view class="tr" wx:for="{{listdata}}" wx:key="">
        <view class="td">
        <checkbox value="{{item.code}}" checked="{{item.checked}}" />
        </view>
        <view class="td" value="{{item.text}}">{{item.code}}</view>
        <view class="td" value="{{item.text}}">{{item.text}}</view>
    </view>
</checkbox-group>

wxss文件

.table{
background-color: #fff;
border:1px solid #dadada;
width:1200rpx;
margin-left:0rpx;
}

.tr{
background-color: #dadada;
white-space: nowrap;
width:100%;
display: flex;
text-align: center;
justify-content: center;
}

.th{
background-color: #fff999;
text-align: center;
justify-content: center;
width: 100%;
border-bottom: 1px solid #dadada;
border-right: 1px solid #dadada;
}

.td{
background-color: #fff;
text-align: center;
justify-content: center;
width: 100%;
border-bottom: 1px solid #dadada;
border-right: 1px solid #dadada;

}

js文件

page({
  data: {
    select_all: false,
    listdata: [
      { code: "1", text: "测试1" },
      { code: "2", text: "测试2"},
      { code: "3", text: "测试3"}
    ],
    batchids: '',    //选中的ids
  },

//全选与反全选
selectall: function (e) {
  console.log(e)
    var that = this;
    var arr = [];   //存放选中id的数组
    for (let i = 0; i < that.data.listdata.length; i++) {

      that.data.listdata[i].checked = (!that.data.select_all)

      if (that.data.listdata[i].checked == true){
        // 全选获取选中的值
        arr = arr.concat(that.data.listdata[i].code.split(','));
      }
    }
  console.log(arr)
    that.setdata({
      listdata: that.data.listdata,
      select_all: (!that.data.select_all),
      batchids:arr
    })
  },

  // 单选
  checkboxchange: function (e) {
    console.log(e.detail.value)
    this.setdata({
      batchids: e.detail.value  //单个选中的值
    })
  },
})

效果图：