小程序裁剪图片上传头像，二维码源码

微信小程序 图片裁剪工具，简单易用

项目需求

在做微信小程序的时候有个图片上传之前裁剪的需求，找过一些github中的项目，都不太理想，主要是没有办法自定义宽高，于是自己研究了一下，做了一个简单的图片裁剪效果

使用方法

项目里面直接放的该功能的文件，将这个文件夹复制到小程序项目中，在app.json中启动该页面即可看到效果

微信小程序技术比较新，所以在网上找了很久都没有找到理想的裁剪插件，正好这两天不是很忙就自己查找资料做了，经过一天的努力终于把它做出来了，不容易啊，现在把它分享给你们（可为你门节省一天开发时间哦）：

wxml：

<!--图片展示 -->
 <view bindtap='upEwm' data-which='1' >
  <view>第一个图</view>
   <image style='200rpx;height:200rpx;background-color:red' src='{{headImg}}'></image>
</view>
<view bindtap='upEwm'  data-which='2' >
  <view>第二个图</view>
   <image style='200rpx;height:200rpx;background-color:red' src='{{ewmImg}}'></image>
</view>
 
 
<!--裁剪图片浮层-->
<view class='fixed-upimg'  wx:if="{{imageFixed}}">
<view class="wx-content-info" >
<!-- <view class="wx-content-info" wx:if="{{imageSrc}}"> -->
  <view wx:if="{{isShowImg}}" class="wx-corpper" style="{{cropperInitW}}rpx;height:{{cropperInitH}}rpx;background:#000">
    <view bindtap='upLoad'  class="wx-corpper-content" style="{{cropperW}}rpx;height:{{cropperH}}rpx;left:{{cropperL}}rpx;top:{{cropperT}}rpx">
      <image src="{{imageSrc}}" style="{{cropperW}}rpx;height:{{cropperH}}rpx"></image>
      <view class="wx-corpper-crop-box" bindtouchstart="contentStartMove" bindtouchmove="contentMoveing" style="{{cutW}}rpx;height:{{cutH}}rpx;left:{{cutL}}rpx;top:{{cutT}}rpx">
        <view class="wx-cropper-view-box">
          <!-- <view class="wx-cropper-viewer">
            <image src="{{imageSrc}}" style="{{cropperW}}rpx;height:{{cropperH}}rpx;left:{{cropperL - cutL}}rpx;top:{{cropperT - cutT}}rpx"></image>
          </view> -->
          <view class="wx-cropper-dashed-h"></view>
          <view class="wx-cropper-dashed-v"></view>
          <view class="wx-cropper-line-t" data-drag="top" catchtouchstart="dragStart" catchtouchmove="dragMove"></view>
          <view class="wx-cropper-line-r" data-drag="right" catchtouchstart="dragStart" catchtouchmove="dragMove"></view>
          <view class="wx-cropper-line-b" data-drag="bottom" catchtouchstart="dragStart" catchtouchmove="dragMove"></view>
          <view class="wx-cropper-line-l" data-drag="left" catchtouchstart="dragStart" catchtouchmove="dragMove"></view>
          <view class="wx-cropper-point point-t" data-drag="top" catchtouchstart="dragStart" catchtouchmove="dragMove"></view>
          <view class="wx-cropper-point point-tr" data-drag="topTight"></view>
          <view class="wx-cropper-point point-r" data-drag="right" catchtouchstart="dragStart" catchtouchmove="dragMove"></view>
          <view class="wx-cropper-point point-rb" data-drag="rightBottom" catchtouchstart="dragStart" catchtouchmove="dragMove"></view>
          <view class="wx-cropper-point point-b" data-drag="bottom" catchtouchstart="dragStart" catchtouchmove="dragMove"></view>
          <view class="wx-cropper-point point-bl" data-drag="bottomLeft"></view>
          <view class="wx-cropper-point point-l" data-drag="left" catchtouchstart="dragStart" catchtouchmove="dragMove"></view>
          <view class="wx-cropper-point point-lt" data-drag="leftTop"></view>
        </view>
      </view>
    </view>
    <!-- <view class="wx-cropper-drag-box"></view> -->
  </view>
  <canvas canvas-id="myCanvas" style="position:absolute;border: 1px solid red; {{imageW}}rpx;height:{{imageH}}rpx;top:-9999px;left:-9999px;"></canvas>
  <button type="primary" bindtap="getImageInfo" style="position:fixed;bottom:120rpx;90%;left:50%;transform:translate3d(-50%,0,0)"> 确认提交 </button>
 
</view>
</view>

　　

// pages/wx-cropper/index.js
// 手机的宽度
var windowWRPX = 750
// 拖动时候的 pageX
var pageX = 0
// 拖动时候的 pageY
var pageY = 0
 
var pixelRatio = wx.getSystemInfoSync().pixelRatio
 
// 调整大小时候的 pageX
var sizeConfPageX = 0
// 调整大小时候的 pageY
var sizeConfPageY = 0
 
var initDragCutW = 0
var initDragCutL = 0
var initDragCutH = 0
var initDragCutT = 0
 
// 移动时 手势位移与 实际元素位移的比
var dragScaleP = 2
 
Page({
  /**
   * 页面的初始数据
   */
  data: {
    imageNum:'', //上传的图片id
    headImg:'', //头像上传
    ewmImg:'', //二维码上传
    imageFixed:false, //裁剪浮层
    // imageSrc: 'http://topmdrt-static.oss-cn-shenzhen.aliyuncs.com/images/testimg2.jpeg',
    imageSrc: '', //要裁剪的图片
    returnImage: '',
    isShowImg: false,
    // 初始化的宽高
    cropperInitW: windowWRPX,
    cropperInitH: windowWRPX,
    // 动态的宽高
    cropperW: windowWRPX,
    cropperH: windowWRPX,
    // 动态的left top值
    cropperL: 0,
    cropperT: 0,
 
    // 图片缩放值
    scaleP: 0,
    imageW: 0,
    imageH: 0,
 
    // 裁剪框 宽高
    cutW: 400,
    cutH: 400,
    cutL: 0,
    cutT: 0,
  },
 
  /**
   * 生命周期函数--监听页面加载
   */
  onReady: function (options) {
  },
 
  /**
   * 生命周期函数--监听页面初次渲染完成
   */
  onLoad: function () {
    var _this = this
     
    // wx.showLoading({
    //   title: '图片加载中...',
    // })
 
    wx.getImageInfo({
      src: _this.data.imageSrc,
      success: function success(res) {
        var innerAspectRadio = res.width / res.height;
        console.log(innerAspectRadio)
        // 根据图片的宽高显示不同的效果   保证图片可以正常显示
        if (innerAspectRadio >= 1) {
          _this.setData({
            cropperW: windowWRPX,
            cropperH: windowWRPX / innerAspectRadio,
            // 初始化left right
            cropperL: Math.ceil((windowWRPX - windowWRPX) / 2),
            cropperT: Math.ceil((windowWRPX - windowWRPX / innerAspectRadio) / 2),
            // 裁剪框  宽高 
            // cutW: windowWRPX - 200,
            // cutH: windowWRPX / innerAspectRadio - 200,
            cutL: Math.ceil((windowWRPX - windowWRPX + 340) / 2),
            cutT: Math.ceil((windowWRPX / innerAspectRadio - (windowWRPX / innerAspectRadio - 20)) / 2),
            // 图片缩放值
            scaleP: res.width * pixelRatio / windowWRPX,
            // 图片原始宽度 rpx
            imageW: res.width * pixelRatio,
            imageH: res.height * pixelRatio
          })
        } else {
          _this.setData({
            cropperW: windowWRPX * innerAspectRadio,
            cropperH: windowWRPX,
            // 初始化left right
            cropperL: Math.ceil((windowWRPX - windowWRPX * innerAspectRadio) / 2),
            cropperT: Math.ceil((windowWRPX - windowWRPX) / 2),
            // 裁剪框的宽高
            // cutW: windowWRPX * innerAspectRadio - 66,
            // cutH: 400,
            cutL: Math.ceil((windowWRPX * innerAspectRadio - (windowWRPX * innerAspectRadio - 20)) / 2),
            cutT: Math.ceil((windowWRPX - 340) / 2),
            // 图片缩放值
            scaleP: res.width * pixelRatio / windowWRPX,
            // 图片原始宽度 rpx
            imageW: res.width * pixelRatio,
            imageH: res.height * pixelRatio
          })
        }
        _this.setData({
          isShowImg: true
        })
        wx.hideLoading()
      }
    })
  },
 
  // 拖动时候触发的touchStart事件
  contentStartMove (e) {
    pageX = e.touches[0].pageX
    pageY = e.touches[0].pageY
  },
 
  // 拖动时候触发的touchMove事件
  contentMoveing (e) {
    var _this = this
    // _this.data.cutL + (e.touches[0].pageX - pageX)
    // console.log(e.touches[0].pageX)
    // console.log(e.touches[0].pageX - pageX)
    var dragLengthX = (pageX - e.touches[0].pageX) * dragScaleP
    var dragLengthY = (pageY - e.touches[0].pageY) * dragScaleP
    var minX = Math.max(_this.data.cutL - (dragLengthX), 0)
    var minY = Math.max(_this.data.cutT - (dragLengthY), 0)
    var maxX = _this.data.cropperW - _this.data.cutW
    var maxY = _this.data.cropperH - _this.data.cutH
    this.setData({
      cutL: Math.min(maxX, minX),
      cutT: Math.min(maxY, minY),
    })
    console.log(`${maxX} ----- ${minX}`)
    pageX = e.touches[0].pageX
    pageY = e.touches[0].pageY
  },
 
  // 获取图片
  getImageInfo () {
    var _this = this
    console.log('shengcheng:'+_this.data.imageSrc)
    wx.showLoading({
      title: '图片生成中...',
    })
    // wx.downloadFile({
    //   url:_this.data.imageSrc, //仅为示例，并非真实的资源     
    //   success: function (res) {
        // 将图片写入画布             
        const ctx = wx.createCanvasContext('myCanvas')
        // ctx.drawImage(res.tempFilePath)
        ctx.drawImage(_this.data.imageSrc)
         
        ctx.draw(true, () => {
          // 获取画布要裁剪的位置和宽度   均为百分比 * 画布中图片的宽度    保证了在微信小程序中裁剪的图片模糊  位置不对的问题
          var canvasW = (_this.data.cutW / _this.data.cropperW) * (_this.data.imageW / pixelRatio)
          var canvasH = (_this.data.cutH / _this.data.cropperH) * (_this.data.imageH / pixelRatio)
          var canvasL = (_this.data.cutL / _this.data.cropperW) * (_this.data.imageW / pixelRatio)
          var canvasT = (_this.data.cutT / _this.data.cropperH) * (_this.data.imageH / pixelRatio)
          console.log(`canvasW:${canvasW} --- canvasH: ${canvasH} --- canvasL: ${canvasL} --- canvasT: ${canvasT} -------- _this.data.imageW: ${_this.data.imageW}  ------- _this.data.imageH: ${_this.data.imageH} ---- pixelRatio ${pixelRatio}`)
          wx.canvasToTempFilePath({
            x: canvasL,
            y: canvasT,
             canvasW,
            height: canvasH,
            destWidth: canvasW,
            destHeight: canvasH,
            canvasId: 'myCanvas',
            success: function (res) {
              wx.hideLoading()
              // 成功获得地址的地方
              console.log('end:'+res.tempFilePath)
              // 判断时上传头像还是二维码
              _this.setData({
                imageFixed: false,
              })
              if (_this.data.imageNum == '1') {
                _this.setData({
                  headImg: res.tempFilePath
                })
              } else if (_this.data.imageNum == '2') {
                _this.setData({
                  ewmImg: res.tempFilePath
                })
              }
 
            }
          })
        })
    //   }
 
 
    // })
  },
 
  // 设置大小的时候触发的touchStart事件
  dragStart(e) {
    var _this = this
    sizeConfPageX = e.touches[0].pageX
    sizeConfPageY = e.touches[0].pageY
    initDragCutW = _this.data.cutW
    initDragCutL = _this.data.cutL
    initDragCutT = _this.data.cutT
    initDragCutH = _this.data.cutH
  },
  
  // 设置大小的时候触发的touchMove事件
  dragMove (e) {
    var _this = this
    var dragType = e.target.dataset.drag
    switch (dragType) {
      case 'right':
        var dragLength = (sizeConfPageX - e.touches[0].pageX) * dragScaleP
        if (initDragCutW >= dragLength) {
          // 如果 移动小于0 说明是在往下啦  放大裁剪的高度  这样一来 图片的高度  最大 等于 图片的top值加 当前图片的高度  否则就说明超出界限
          if (dragLength < 0 && _this.data.cropperW > initDragCutL + _this.data.cutW) {
            this.setData({
              cutW: initDragCutW - dragLength
            })
          }
          // 如果是移动 大于0  说明在缩小  只需要缩小的距离小于原本裁剪的高度就ok
          if (dragLength > 0) {
            this.setData({
              cutW: initDragCutW - dragLength
            })
          }
          else {
            return
          }
        } else {
          return
        }
        break;
      case 'left':
        var dragLength = (dragLength = sizeConfPageX - e.touches[0].pageX) * dragScaleP
        console.log(dragLength)
        if (initDragCutW >= dragLength && initDragCutL > dragLength) {
          if (dragLength < 0 && Math.abs(dragLength) >= initDragCutW) return
          this.setData({
            cutL: initDragCutL - dragLength,
            cutW: initDragCutW + dragLength
          })
        } else {
          return;
        }
        break;
      case 'top':
        var dragLength = (sizeConfPageY - e.touches[0].pageY) * dragScaleP
        if (initDragCutH >= dragLength && initDragCutT > dragLength) {
          if (dragLength < 0 && Math.abs(dragLength) >= initDragCutH) return
          this.setData({
            cutT: initDragCutT - dragLength,
            cutH: initDragCutH + dragLength
          })
        } else {
          return;
        }
        break;
      case 'bottom':
        var dragLength = (sizeConfPageY - e.touches[0].pageY) * dragScaleP
        // console.log(_this.data.cropperH > _this.data.cutT + _this.data.cutH)
        console.log(dragLength)
        console.log(initDragCutH >= dragLength)
        console.log(_this.data.cropperH > initDragCutT + _this.data.cutH)
        // 必须是 dragLength 向上缩小的时候必须小于原本的高度
        if (initDragCutH >= dragLength) {
          // 如果 移动小于0 说明是在往下啦  放大裁剪的高度  这样一来 图片的高度  最大 等于 图片的top值加 当前图片的高度  否则就说明超出界限
          if (dragLength < 0 && _this.data.cropperH > initDragCutT + _this.data.cutH) {
            this.setData({
              cutH: initDragCutH - dragLength
            })
          }
          // 如果是移动 大于0  说明在缩小  只需要缩小的距离小于原本裁剪的高度就ok
          if (dragLength > 0) {
            this.setData({
              cutH: initDragCutH - dragLength
            })
          }
          else{
            return
          }
        } else {
          return
        }
        break;
      case 'rightBottom':
        var dragLengthX = (sizeConfPageX - e.touches[0].pageX) * dragScaleP
        var dragLengthY = (sizeConfPageY - e.touches[0].pageY)  * dragScaleP
        if (initDragCutH >= dragLengthY && initDragCutW >= dragLengthX) {
          // bottom 方向的变化
          if ((dragLengthY < 0 && _this.data.cropperH > initDragCutT + _this.data.cutH) || (dragLengthY > 0)) {
            this.setData({
              cutH: initDragCutH - dragLengthY
            })
          }
 
          // right 方向的变化
          if ((dragLengthX < 0 && _this.data.cropperW > initDragCutL + _this.data.cutW) || (dragLengthX > 0)) {
            this.setData({
              cutW: initDragCutW - dragLengthX
            })
          }
          else {
            return
          }
        } else {
          return
        }
        break;
      default:
        break;
    }
  },
  // 图片上传
  upLoad: function () {
  
  },
  upEwm: function(e){
    var _this = this
    wx.chooseImage({
      count: 1, // 默认9
      sizeType: ['original', 'compressed'], // 可以指定是原图还是压缩图，默认二者都有
      sourceType: ['album', 'camera'], // 可以指定来源是相册还是相机，默认二者都有
      success: function (res) {
        // 返回选定照片的本地文件路径列表，tempFilePath可以作为img标签的src属性显示图片
        var tempFilePaths = res.tempFilePaths;
        // var mode = parseFloat(e.currentTarget.dataset.current);
        console.log('shangchuan:' + tempFilePaths)
        console.log(e.currentTarget.dataset.which);
        _this.setData({
          imageFixed: true,
          imageSrc: tempFilePaths.join(),
          imageNum: e.currentTarget.dataset.which
        })
        // start
        wx.getImageInfo({
          src: _this.data.imageSrc,
          success: function success(res) {
            var innerAspectRadio = res.width / res.height;
            console.log('bili'+innerAspectRadio)
            // 根据图片的宽高显示不同的效果   保证图片可以正常显示
          
             
            if (innerAspectRadio == '1') {
              console.log('zhengfangxingtu')
              _this.setData({
                imageFixed: false,
              })
              // 判断时上传头像还是二维码
              if (_this.data.imageNum == '1') {
                _this.setData({
                  headImg: tempFilePaths.join()
                })
              } else if (_this.data.imageNum == '2') {
                _this.setData({
                  ewmImg: tempFilePaths.join()
                })
              }
            
            } else if (innerAspectRadio > 1) {
              _this.setData({
                cropperW: windowWRPX,
                cropperH: windowWRPX / innerAspectRadio,
                // 初始化left right
                cropperL: Math.ceil((windowWRPX - windowWRPX) / 2),
                cropperT: Math.ceil((windowWRPX - windowWRPX / innerAspectRadio) / 2),
                // 裁剪框  宽高 
                // cutW: windowWRPX - 200,
                // cutH: windowWRPX / innerAspectRadio - 200,
                cutL: Math.ceil((windowWRPX - windowWRPX + 340) / 2),
                cutT: Math.ceil((windowWRPX / innerAspectRadio - (windowWRPX / innerAspectRadio - 20)) / 2),
                // 图片缩放值
                scaleP: res.width * pixelRatio / windowWRPX,
                // 图片原始宽度 rpx
                imageW: res.width * pixelRatio,
                imageH: res.height * pixelRatio
              })
            } else {
              _this.setData({
                cropperW: windowWRPX * innerAspectRadio,
                cropperH: windowWRPX,
                // 初始化left right
                cropperL: Math.ceil((windowWRPX - windowWRPX * innerAspectRadio) / 2),
                cropperT: Math.ceil((windowWRPX - windowWRPX) / 2),
                // 裁剪框的宽高
                // cutW: windowWRPX * innerAspectRadio - 66,
                // cutH: 400,
                cutL: Math.ceil((windowWRPX * innerAspectRadio - (windowWRPX * innerAspectRadio - 20)) / 2),
                cutT: Math.ceil((windowWRPX - 340) / 2),
                // 图片缩放值
                scaleP: res.width * pixelRatio / windowWRPX,
                // 图片原始宽度 rpx
                imageW: res.width * pixelRatio,
                imageH: res.height * pixelRatio
              })
            }
            _this.setData({
              isShowImg: true
            })
            wx.hideLoading()
          }
        })
 
        // end
      }
    })
  },
  /**
   * 生命周期函数--监听页面显示
   */
  onShow: function () {
   
  },
 
  /**
   * 生命周期函数--监听页面隐藏
   */
  onHide: function () {
   
  },
 
  /**
   * 生命周期函数--监听页面卸载
   */
  onUnload: function () {
   
  },
 
  /**
   * 页面相关事件处理函数--监听用户下拉动作
   */
  onPullDownRefresh: function () {
   
  },
 
  /**
   * 页面上拉触底事件的处理函数
   */
  onReachBottom: function () {
   
  },
 
  /**
   * 用户点击右上角分享
   */
  onShareAppMessage: function () {
   
  }
})

　　

/* pages/wx-cropper/index.wxss */
.fixed-upimg{
    position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: #fff;
}
.wx-content-info{
  position: fixed;
  top: 130rpx;
  left: 0;
  right: 0;
  bottom: 0;
 
}
 
.wx-corpper{
  position: relative;
  overflow: hidden;
  -webkit-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  user-select: none;
  -webkit-tap-highlight-color: transparent;
  -webkit-touch-callout: none;
  box-sizing: border-box;
}
 
.wx-corpper-content{
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
}
 
.wx-corpper-content image {
    display: block;
     100%;
    min- 0 !important;
    max- none !important;
    height: 100%;
    min-height: 0 !important;
    max-height: none !important;
    image-orientation: 0deg !important;
    margin: 0 auto;
}
 
/* 移动图片效果 */
.wx-cropper-drag-box{
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    cursor: move;
    background: rgba(0,0,0,0.6);
    z-index: 1;
}
 
/* 内部的信息 */
.wx-corpper-crop-box{
    position: absolute;
     500rpx;
    height: 500rpx;
    background: rgba(255,255,255,0.3);
    z-index: 2;
}
 
.wx-corpper-crop-box .wx-cropper-view-box {
    position: relative;
    display: block;
     100%;
    height: 100%;
    overflow: visible;
    outline: 1px solid #69f;
    outline-color: rgba(102, 153, 255, .75)
}
 
/* 横向虚线 */
.wx-cropper-dashed-h{
    position: absolute;
    top: 33.33333333%;
    left: 0;
     100%;
    height: 33.33333333%;
    border-top: 1px dashed rgba(255,255,255,0.5);
    border-bottom: 1px dashed rgba(255,255,255,0.5);
}
 
/* 纵向虚线 */
.wx-cropper-dashed-v{
    position: absolute;
    left: 33.33333333%;
    top: 0;
     33.33333333%;
    height: 100%;
    border-left: 1px dashed rgba(255,255,255,0.5);
    border-right: 1px dashed rgba(255,255,255,0.5);
}
 
/* 四个方向的线  为了之后的拖动事件*/
.wx-cropper-line-t{
    position: absolute;
    display: block;
     100%;
    background-color: #69f;
    top: 0;
    left: 0;
    height: 1px;
    opacity: 0.1;
    cursor: n-resize;
}
 
.wx-cropper-line-t::before{
  content: '';
  position: absolute;
  top: 50%;
  right: 0rpx;
   100%;
  -webkit-transform: translate3d(0,-50%,0);
  transform: translate3d(0,-50%,0);
  bottom: 0;
  height: 41rpx;
  background: transparent;
  z-index: 11;
}
 
.wx-cropper-line-r{
    position: absolute;
    display: block;
    background-color: #69f;
    top: 0;
    right: 0px;
     1px;
    opacity: 0.1;
    height: 100%;
    cursor: e-resize;
}
.wx-cropper-line-r::before{
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
   41rpx;
  -webkit-transform: translate3d(-50%,0,0);
  transform: translate3d(-50%,0,0);
  bottom: 0;
  height: 100%;
  background: transparent;
  z-index: 11;
}
 
.wx-cropper-line-b{
    position: absolute;
    display: block;
     100%;
    background-color: #69f;
    bottom: 0;
    left: 0;
    height: 1px;
    opacity: 0.1;
    cursor: s-resize;
}
 
.wx-cropper-line-b::before{
  content: '';
  position: absolute;
  top: 50%;
  right: 0rpx;
   100%;
  -webkit-transform: translate3d(0,-50%,0);
  transform: translate3d(0,-50%,0);
  bottom: 0;
  height: 41rpx;
  background: transparent;
  z-index: 11;
}
 
.wx-cropper-line-l{
    position: absolute;
    display: block;
    background-color: #69f;
    top: 0;
    left: 0;
     1px;
    opacity: 0.1;
    height: 100%;
    cursor: w-resize;
}
.wx-cropper-line-l::before{
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
   41rpx;
  -webkit-transform: translate3d(-50%,0,0);
  transform: translate3d(-50%,0,0);
  bottom: 0;
  height: 100%;
  background: transparent;
  z-index: 11;
}
 
.wx-cropper-point{
     5px;
    height: 5px;
    background-color: #69f;
    opacity: .75;
    position: absolute;
    z-index: 3;
}
 
.point-t{
    top: -3px;
    left: 50%;
    margin-left: -3px;
    cursor: n-resize;
}
 
.point-tr{
    top: -3px;
    left: 100%;
    margin-left: -3px;
    cursor: n-resize;
}
 
.point-r{
    top: 50%;
    left:100%;
    margin-left: -3px;
    margin-top: -3px;
    cursor: n-resize;
}
 
.point-rb{
    left: 100%;
    top: 100%;
    -webkit-transform: translate3d(-50%,-50%,0);
    transform: translate3d(-50%,-50%,0);
    cursor: n-resize;
     24rpx;
    height: 24rpx;
    background-color: #69f;
    position: absolute;
    z-index: 1112;
    opacity: 1;
}
 
.point-b{
    left:50%;
    top: 100%;
    margin-left: -3px;
    margin-top: -3px;
    cursor: n-resize;
}
 
.point-bl{
    left:0%;
    top: 100%;
    margin-left: -3px;
    margin-top: -3px;
    cursor: n-resize;
}
 
.point-l{
    left:0%;
    top: 50%;
    margin-left: -3px;
    margin-top: -3px;
    cursor: n-resize;
}
 
.point-lt{
    left:0%;
    top: 0%;
    margin-left: -3px;
    margin-top: -3px;
    cursor: n-resize;
}
 
/* 裁剪框预览内容 */
.wx-cropper-viewer{
  position: relative;
   100%;
  height: 100%;
  overflow: hidden;
}
 
.wx-cropper-viewer image{
  position: absolute;
  z-index: 2;
}