微信小程序开发图片拖拽实例详解

<view class="container">   <view class="cnt">     <image class="image-style" src="../uploads/foods.jpg" style="left:{{ballleft}}px;width:{{screenWidth}}px" bindtouchmove="ballMoveEvent">     </image>   </view> </view> 

.container {   box-sizing:border-box;   padding:1rem; } .cnt{   width:100%;   height:15rem;   border: 1px solid #ccc;   position:relative;   overflow: hidden; } .image-style{    position: absolute;    top: 0px;    left:0px;    height:100%;  }  

var app = getApp() Page({   data: {     ballleft:-20,     screenWidth: 0,   },   onLoad: function() {     var _this = this;     wx.getSystemInfo({       success: function(res) {         _this.setData({           screenHeight: res.windowHeight,           screenWidth: res.windowWidth,         });       }     });    },   ballMoveEvent: function(e) {     var touchs = e.touches[0];     var pageX = touchs.pageX;     console.log('宽度 '+this.data.screenWidth)     console.log('pageX: ' + pageX);     //这里用right和bottom.所以需要将pageX pageY转换      var x = this.data.screenWidth/2 - pageX-20;     if(this.data.screenWidth>385){       if(x>42){x=42;}     }else{       if(x>32){x=32;}     }     if(x<0){x=0;}     console.log('x:' + x)     this.setData({       ballleft: -x     });   } })