<view class='selection'>
 <view class='{{view1}}' bindtap='view1Click' id='1'>a</view>
 <view class='{{view2}}' bindtap='view2Click' id='2'>b</view>
 <view class='{{view3}}' bindtap='view3Click' id='3'>c</view>
 <view class='{{view4}}' bindtap='view4Click' id='4'>d</view>
</view>

Page({ 
 
 /** 
  * 页面的初始数据 
  */ 
 data: { 
  view1: 'selection1', 
  view2: 'selection1', 
  view3: 'selection1', 
  view4: 'selection1', 
  // 默认答案为2，后台会给的 
  key: 2, 
  // 选项是否被点击 
  isSelect: false 
 }, 
 
 view1Click: function(e) { 
  var select = e.target.id 
  // 选项没被选择时将执行 
  if (!this.data.isSelect) { 
   // 将选项设置为“已被选择” 
   this.setData({ 
    isSelect: true 
   }) 
   // 注意！此处必须是'=='而不是'=' 
   if (select == this.data.key) { 
    this.setData({ 
     view1: 'selection2' 
    }) 
   } else { 
    this.setData({ 
     view1: 'selection3' 
    }) 
    // 将正确选项显示出来 
    this.showAnswer(this.data.key) 
   } 
 
  } 
 }, 
 view2Click: function(e) { 
  var select = e.target.id 
  // 选项没被选择时将执行 
  if (!this.data.isSelect) { 
   this.setData({ 
    isSelect: true 
   }) 
   // 注意！此处必须是'=='而不是'=' 
   if (select == this.data.key) { 
    this.setData({ 
     view2: 'selection2' 
    }) 
   } else { 
    this.setData({ 
     view2: 'selection3' 
    }) 
    // 将正确选项显示出来 
    this.showAnswer(this.data.key) 
   } 
 
  } 
 }, 
 view3Click: function(e) { 
  var select = e.target.id 
  // 选项没被选择时将执行 
  if (!this.data.isSelect) { 
   this.setData({ 
    isSelect: true 
   }) 
   // 注意！此处必须是'=='而不是'=' 
   if (select == this.data.key) { 
    this.setData({ 
     view3: 'selection2' 
    }) 
   } else { 
    this.setData({ 
     view3: 'selection3' 
    }) 
    // 将正确选项显示出来 
    this.showAnswer(this.data.key) 
   } 
 
  } 
 }, 
 view4Click: function(e) { 
  var select = e.target.id 
  // 选项没被选择时将执行 
  if (!this.data.isSelect) { 
   this.setData({ 
    isSelect: true 
   }) 
   // 注意！此处必须是'=='而不是'=' 
   if (select == this.data.key) { 
    this.setData({ 
     view4: 'selection2' 
    }) 
   } else { 
    this.setData({ 
     view4: 'selection3' 
    }) 
    // 将正确选项显示出来 
    this.showAnswer(this.data.key) 
   } 
 
  } 
 }, 
 showAnswer: function(key) { 
  // 通过swith语句判断正确答案，从而显示正确选项 
  switch (key) { 
   case 1: 
    this.setData({ 
     view1: 'selection2' 
    }) 
    break; 
   case 2: 
    this.setData({ 
     view2: 'selection2' 
    }) 
    break; 
   case 3: 
    this.setData({ 
     view3: 'selection2' 
    }) 
    break; 
   default: 
    this.setData({ 
     view4: 'selection2' 
    }) 
  } 
 } 
})

.selection1{
width: 400rpx;
height: 150rpx;
background-color: grey;

display: flex;
flex-direction: column;
justify-content: space-around;
align-items: center;
}
.selection2{
width: 400rpx;
height: 150rpx;
background-color: blue;
display: flex;
flex-direction: column;
justify-content: space-around;
align-items: center;
}
.selection3{
width: 400rpx;
height: 150rpx;
background-color: red;
display: flex;
flex-direction: column;
justify-content: space-around;
align-items: center;
}
.selection{
width: 750rpx;
height: 800rpx;
display: flex;
flex-direction: column;
justify-content: space-around;
align-items: center;
}