efunbox-schedule-miniApps/compontents/preview/preview.js

// compontents/lesson_list/lessonList.js
Component({
  /**
   * 组件的属性列表
   */
  properties: {
    materialData: {
      type: Array,
      value: []
    },
    height: {
      type: String,
      value: ''
    }
  },

  /**
   * 组件的初始数据
   */
  data: {
    flag: false,
    animationData: {},
    downUp: '展开',
    src: '../../pages/image/toDown.png'
  },

  /**
   * 组件的方法列表
   */
  methods: {
    onTap (e) {
      let flage = e.target.dataset.flag;
      const height = this.properties.materialData.length * 70;
      if(flage){
        
        this.util(flage, '280rpx');
        this.setData({
          'flag': false,
          'downUp': '展开',
          'src': '../../pages/image/toDown.png'
        })
      } else {
        this.util(flage, height + 'rpx');
        this.setData({
          'flag': true,
          'downUp': '收起',
          'src': '../../pages/image/toUp.png'
        })
      }
    },
    /* 创建动画并执行 */
    util (flag, height) {
      // 创建动画实例   
      var animation = wx.createAnimation({  
        duration: 200,  //动画时长  
        timingFunction: "linear", //线性  
        delay: 0  //0则不延迟  
      });
      
      this.animation = animation;

      animation.height(height).step();

      this.setData({  
        animationData: animation.export()  
      })  
    },
    //点击预览图片
    preview (e) { 
      const warePath = e.currentTarget.dataset.warepath;
      wx.downloadFile({
        url: warePath,
        success: function (res) {
          var filePath = res.tempFilePath
          wx.openDocument({
            filePath: filePath,
            success: function (res) {
              console.log('打开文档成功')
            }
          })
        }
      })
    }
  }
})