微信小程序实现给循环列表点击添加类（单项和多项）

在微信小程序里面没有DOM对象, 不能操作DOM. 所有的操作通过数据来实现，下面主要实现了给循环列表点击添加类的操作

一、单项

目标需求：实现下图，给点击的view增加类，每次只能选择一个。

主要思路：给点击的view增加类，依靠点击的index对state进行赋值。如果相同时，给该view增加类。

实现代码：

.wxml文件

 <view>
   <view class='appointent-date'>
     <view  class="appointent-date-div {{state==index?'active-tag':''}}" bindtap="select_date"  wx:for="{{dates}}" data-key='{{index}}'>
       <view class="flex-item" >
         <rich-text class='data_name'>{{item.data_name}}</rich-text>
         <rich-text>{{item.name}}</rich-text>
       </view>
     </view>
   </view>
 </view>

.wxss文件

 .appointent-date-div{
   display:inline-block;
   width:20%;
   text-align: center;
   margin-top: 30rpx;
 }
 .flex-item{
   display: inline-block;
   width:96rpx;
   height: 88rpx;
   font-size: 26rpx;
   border:2rpx solid #999;
   text-align: center;
   border-radius: 10rpx;
   color: #999;
   cursor: pointer;
   line-height: 30rpx;
 }
 .data_name{
   font-size: 36rpx;
   line-height: 52rpx;

 }
 .active-tag .flex-item{
   background: #c8321e;
   color:#fff;
   border:1rpx solid #fff;
 }

.js文件

 Page({

   /**
    * 页面的初始数据
    */
   data: {
     dates: [
       { "data_name": "30", "name": "十三"},
       { "data_name": "1", "name": "十四"},
       { "data_name": "2", "name": "十五"},
       { "data_name": "3", "name": "十六"},
       { "data_name": "4", "name": "十七"},
       { "data_name": "5", "name": "十八"},
       { "data_name": "6", "name": "十九"},
       { "data_name": "7", "name": "二十"},
       { "data_name": "8", "name": "廿一"},
       { "data_name": "9", "name": "廿二"},
       { "data_name": "10", "name": "廿三"},
       { "data_name": "11", "name": "廿四"},
       { "data_name": "12", "name": "廿五"},
       { "data_name": "13", "name": "廿六"},
       { "data_name": "14", "name": "廿七"}
     ],
     state:''
   },
   //选择日期后加样式
   select_date: function (e) {
     this.setData({
       state: e.currentTarget.dataset.key,
     });
   },
 })

二，多项

目标需求：实现下图，给点击的view增加类，再次点击时取消，可以多项选择。

主要思路：

给dates数组增加一个属性state, 1表示状态选中,0表示未选中，每次点击时修改state的值。

实现代码：

.wxml文件

 <view class='appointent-date'>
     <view  class="appointent-date-div {{item.state==1?'active-tag':''}}" bindtap="select_date"  wx:for="{{dates}}" data-key='{{index}}'>
       <view class="flex-item" >
         <rich-text class='data_name'>{{item.data_name}}</rich-text>
         <rich-text>{{item.name}}</rich-text>
       </view>
     </view>
   </view>

.wxss文件

 .appointent-date{
   padding:10rpx 30rpx 40rpx 30rpx;
   background: #fff;
   box-sizing: border-box;
 }
 .appointent-date-div{
   display:inline-block;
   width:20%;
   text-align: center;
   margin-top: 30rpx;
 }
 .flex-item{
   display: inline-block;
   width:96rpx;
   height: 88rpx;
   font-size: 26rpx;
   border:2rpx solid #999;
   text-align: center;
   border-radius: 10rpx;
   color: #999;
   cursor: pointer;
   line-height: 30rpx;
 }
 .data_name{
   font-size: 36rpx;
   line-height: 52rpx;

 }
 .active-tag .flex-item{
   background: #c8321e;
   color:#fff;
   border:1rpx solid #fff;
 }

.js文件

 Page({

   /**
    * 页面的初始数据
    */
   data: {
     dates: [
       { "data_name": "30", "name": "十三", "state": 0 },
       { "data_name": "1", "name": "十四", "state": 0 },
       { "data_name": "2", "name": "十五", "state": 0 },
       { "data_name": "3", "name": "十六", "state": 0 },
       { "data_name": "4", "name": "十七", "state": 0 },
       { "data_name": "5", "name": "十八", "state": 0 },
       { "data_name": "6", "name": "十九", "state": 0 },
       { "data_name": "7", "name": "二十", "state": 0 },
       { "data_name": "8", "name": "廿一", "state": 0 },
       { "data_name": "9", "name": "廿二", "state": 0 },
       { "data_name": "10", "name": "廿三", "state": 0 },
       { "data_name": "11", "name": "廿四", "state": 0 },
       { "data_name": "12", "name": "廿五", "state": 0 },
       { "data_name": "13", "name": "廿六", "state": 0 },
       { "data_name": "14", "name": "廿七", "state": 0 }
     ]
   },
   //选择日期后加样式
   select_date: function (e) {
     var index = e.currentTarget.dataset.key;
     if (this.data.dates[index].state == 1) {
       this.data.dates[index].state = 0;
     } else if (this.data.dates[index].state == 0) {
       this.data.dates[index].state = 1;
     }
     this.setData({
       dates: this.data.dates,
     });
   },
 })