<view >
  
    <block wx:for="{{stars}}">
      <image class="star-image" style="left: {{item*100}}rpx" src="{{key > item ?(key-item == 0.5?halfSrc:selectedSrc) : normalSrc}}">
        <view class="item" style="left:0rpx" data-key="{{item+0.5}}" bindtap="selectLeft"></view>
        <view class="item" style="left:50rpx" data-key="{{item+1}}" bindtap="selectRight"></view>
      </image>
    </block>
  <view style="margin-top:450rpx">
    <button bindtap="startRating">确认</button>
  </view>
</view>

.star-image{
  position: absolute;
  top: 50rpx;
  margin-left: 100rpx;
  width: 100rpx;
  height: 100rpx;
  src: "/images/icon/star-no.png";
}
.item{
  position: absolute;
  top: 50rpx;
  width: 100rpx;
  height: 100rpx;
}

//index.js
var app = getApp()
var count = 0;
Page({
  data: {
    stars: [0, 1, 2, 3, 4],
    normalSrc: '/images/icon/star-no.png',
    selectedSrc: '/images/icon/star-full.png',
    halfSrc: '/images/icon/star-half.png',
    key: 0,//评分
    status:'',    //0未课评 1已课评
  },

  /**
     * 生命周期函数--监听页面加载
     */
  onLoad: function (options) {
    console.log(options.status)
  },

  /**
   * 点击左边,半颗星
   */
  selectLeft: function (e) {
    var key = e.currentTarget.dataset.key
    if (this.data.key == 0.5 && e.currentTarget.dataset.key == 0.5) {
      //只有一颗星的时候,再次点击,变为0颗
      key = 0;
    }
    count = key
    this.setData({
      key: key
    })

  },
  /**
   * 点击右边,整颗星
   */
  selectRight: function (e) {
    var key = e.currentTarget.dataset.key
    count = key
    this.setData({
      key: key
    })
  },
  // 确定按钮
  startRating: function (e) {
    wx.showModal({
      title: '分数',
      content: "" + count,
      success: function (res) {
        if (res.confirm) {
          console.log('用户点击确定')
        }
      }
    })
  }
})