.wxml

<view class="index-top">
  <view class="{{index <= curring && curring != 0?'top-blue':'top-currin'}} {{index > 0 && curring < 2?'top-fint':'top-ping'}} {{2 == curring?'top-nux':''}} {{2 < curring?'top-name':''}}" wx:for="{{4}}" wx:key="index">
    <view class="{{index <= curring?'top-buing':'top-bloc'}}">
      <text>√</text>
      <span>{{index+1}}</span>
    </view>
  </view>
</view>
<view class="centent" wx:for="{{detail}}" wx:key="index" wx:if="{{index == number}}">
  <view class="centent-title">{{index+1}}. {{item.title}}</view>
  <radio-group class="centent-group">
    <radio class="group-radio" bindtap="radioChange" wx:for="{{item.array}}" wx:for-item="cell" data-index="{{index}}" data-id="{{item.id}}" wx:key="index" checked="{{cell.usname}}">
      <span class="radio-span" wx:if="{{index == 0}}">A.</span>
      <span class="radio-span" wx:if="{{index == 1}}">B.</span>
      <span class="radio-span" wx:if="{{index == 2}}">C.</span>
      <span class="radio-span" wx:if="{{index == 3}}">D.</span>
      <text>{{cell.name}}</text>
    </radio>
  </radio-group>
</view>
<view class="bottom" wx:if="{{number != detail.length}}">
<view bindtap="previous" wx:if="{{number != 0}}">上一步</view>
<view bindtap="nextstep" style="{{number == 0?'margin:0 30%;':''}}">下一步</view>
</view> 
<view class="submission" wx:if="{{number == detail.length}}">
  <view>
  <image src="https://profile.csdnimg.cn/0/9/6/3_qq_43764578"></image>
  </view>
  <view class="submission-center" bindtap="subsic">提交答案</view>
</view>

.wxss

view{
  box-sizing: border-box;
}
.index-top{
  width: 100%;
  float: left;
  overflow: hidden;
  padding: 3% 5%;
}
.top-currin,.top-blue{
  width: 25%;
  text-align: center;
  float: left;
  overflow: hidden;
  position: relative;
}
.index-top>.top-currin:nth-child(1)::before,.index-top>.top-fint:nth-child(2)::after,.index-top>.top-fint:nth-child(3)::after,.index-top>.top-nux:nth-child(3)::after{
  content: "";
  position: absolute;
  right: 0;
  top: 20rpx;
  width: calc((100% - 80rpx) / 2);
  border-top: 1px solid #ccc;
}
.index-top>.top-currin:nth-child(2)::before,.index-top>.top-currin:nth-child(3)::before,.index-top>.top-currin:nth-child(4)::after{
  content: "";
  position: absolute;
  left: 0rpx;
  top: 20rpx;
  width: calc((100% - 80rpx) / 2);
  border-top: 1px solid #ccc;
}
.top-bloc{
  width: 45rpx;
  height: 45rpx;
  margin: 0 auto;
  line-height:calc(45rpx - 2px);
  border:1px solid #666;
  border-radius:50%;
  font-size: 24rpx; 
  color: #666;
  text-align: center;
}
.index-top>.top-blue:nth-child(1)::before,.index-top>.top-ping:nth-child(2)::after,.top-name:nth-child(3)::after{
  content: "";
  position: absolute;
  right: 0;
  top: 20rpx;
  width: calc((100% - 80rpx) / 2);
  border-top: 1px solid #0081FF;
  transition: all 0.3s ease-in-out 0s;
  transform: translateY(0rpx);
}
.index-top>.top-blue:nth-child(2)::before,.index-top>.top-ping:nth-child(3)::before,.top-name:nth-child(4)::after{
  content: "";
  position: absolute;
  left: 0rpx;
  top: 20rpx;
  width: calc((100% - 80rpx) / 2);
  border-top: 1px solid #0081FF;
  transition: all 0.5s ease-in-out 0s;
  transform: translateY(0rpx);
}
.top-bloc>text{
  position: absolute;
  transform: translateY(-40rpx);
}
.top-buing>span{
  visibility: hidden;
}
.top-buing>text{
  position: absolute;
  transition: all 0.3s ease-in-out 0s;
  transform: translateY(0rpx);
}
.top-buing{
  width: 45rpx;
  height: 45rpx;
  margin: 0 auto;
  line-height:calc(45rpx - 2px);
  border:1px solid #0081FF;
  background-color: #0081FF;
  border-radius:50%;
  font-size: 24rpx; 
  color: #fff;
  transition: all 0.3s ease-in-out 0s;
  transform: translateY(0rpx);
  text-align: center;
}
.centent{
  width: 100%;
  float: left;
  padding: 5% 3% 3% 3%;
  overflow: hidden;
}
.centent-title{
  width: 100%;
  float: left;
  overflow: hidden;
  line-height: 46rpx;
  font-size: 32rpx;
}
.centent-group{
  width: 100%;
  float: left;
  overflow: hidden;
}
.group-radio{
  width: 100%;
  float: left;
  margin-top: 30rpx;
}
.radio-span{
  position: relative;
  top: 2rpx;
  margin: 0 6rpx 0 8rpx
}
.bottom{
  width: 100%;
  float: left;
  overflow: hidden;
  padding: 40rpx 0;
  text-align: center;
}
.bottom>view{
  width: 40%;
  float: left;
  margin: 0 5%;
  background-color: #e03997;
  color: #fff;
  height: 80rpx;
  line-height: 80rpx;
  border-radius: 10rpx;
}
.submission{
  width: 100%;
  float: left;
  overflow: hidden;
  padding: 3%;
  text-align: center;
}
.submission>view>image{
  width: 200rpx;
  height: 200rpx;
  border-radius: 50%;
  margin: 0 auto;
}
.submission-center{
  width: 40%;
  margin: 40rpx 30%;
  height: 80rpx;
  line-height: 80rpx;
  background-color: #e54d42;
  color: #fff;
  border-radius: 10rpx;
}

.js

Page({
  data: {
    curring:-1,
    detail: [
      {
        id: '1', title: 'CSDN：https://blog.csdn.net/qq_43764578 QQ:1010753897',answer:'2',array: [
          { name: '错误答案', usname: false }, { name: '正确答案', usname: false },
          { name: '错误答案', usname: false }, { name: '错误答案', usname: false },
        ]
      },
      {
        id: '2', title: 'CSDN：https://blog.csdn.net/qq_43764578 QQ:1010753897', answer: '1', array: [
          { name: '正确答案', usname: false }, { name: '错误答案', usname: false },
          { name: '错误答案', usname: false }, { name: '错误答案', usname: false },
        ]
      },
      {
        id: '3', title: 'CSDN：https://blog.csdn.net/qq_43764578 QQ:1010753897', answer: '4', array: [
          { name: '错误答案', usname: false }, { name: '错误答案', usname: false },
          { name: '错误答案', usname: false }, { name: '正确答案', usname: false },
        ]
      },
      {
        id: '4', title: 'CSDN：https://blog.csdn.net/qq_43764578 QQ:1010753897', answer: '3',  array: [
          { name: '错误答案', usname: false }, { name: '错误答案', usname: false },
          { name: '正确答案', usname: false }, { name: '错误答案', usname: false },
        ]
      },
    ],
    number: 0,
    answer:0,
  },
  previous:function(e){
    this.setData({
      number: this.data.number-1,
      curring: this.data.curring-1,
    })
  },
  radioChange:function(e){
    let index = e.currentTarget.dataset.index
    let id = e.currentTarget.dataset.id
    let detail = this.data.detail
    for(let i = 0;i<detail.length;i++){
      if(detail[i].id == id){
        detail[i].array[index].usname = true
        for(let j = 0;j<detail[i].array.length;j++){
          if (j != index){
            detail[i].array[j].usname = false
          }
        }
      }
    }
    this.setData({
      detail:detail
    })
  },
  nextstep:function(e){
    let detail = this.data.detail
    let number = this.data.number
    let curring = this.data.curring
    let usname = 0;
    for(let i = 0;i<detail[number].array.length;i++){
      if(!detail[number].array[i].usname){
        usname++
      }
    }
    if(usname == detail[number].array.length){
      wx.showToast({
        title: '答题选项不能为空',
        icon: 'none',
        duration: 2000
      })
      return false;
    }
    curring++
    number++
    if (curring > 3){
      curring = -1
    }
    this.setData({
      curring: curring,
      number: number,
    })
  },
  subsic:function(e){
    let detail = this.data.detail
    let answer = 0
    let letter = ''
    for(let i = 0;i < detail.length;i++){
      for(let j = 0;j < detail[i].array.length;j++){
        if(detail[i].array[j].usname){
          letter = detail[i].answer-1
          if(letter == j){
            answer++
          }
        }
      }
    }
    wx.showToast({
      title: '答对了:' + answer + '题',
      icon: 'none',
      duration: 2000
    })
  },
})