WXML

  <view class="qianzi">
    <view class="paper">
      <canvas class="handWriting" disable-scroll="true" bindtouchstart="touchstart1" bindtouchmove="touchmove1"
        canvas-id="handWriting1">
      </canvas>
    </view>
    <view class="signBtn">
      <button class="btn1" size=""  bindtap="sign1ok">完成签字</button>
      <button class="btn2" size="" bindtap="reSign1">清除签名</button>
    </view>
  </view>

<view class="image" hidden="{{src?false:true}}">
   <image src="{{src}}"></image>
</view>

 

 

JS

data: {     optionsTaskid: '', //接收到的任务id     orderKey: '',     context1: null,     hasDraw: false, //默认没有画     src: null,   },

  
touchstart1: function (e) {
    var context1 = this.data.context1;
    context1.moveTo(e.touches[0].x, e.touches[0].y);
    this.setData({
      context1: context1,
      hasDraw: true, //要签字了
    });
  },
  touchmove1: function (e) {
    var x = e.touches[0].x;
    var y = e.touches[0].y;
    var context1 = this.data.context1;
    context1.setLineWidth(3);
    context1.lineTo(x, y);
    context1.stroke();
    context1.setLineCap('round');
    context1.draw(true);
    context1.moveTo(x, y);
  },
  reSign1: function () { //重新画
    var that = this;
    var context1 = that.data.context1;
    context1.draw(); //清空画布
    that.setData({
      hasDraw: false, //没有画
      src: null
    });
  },

  sign1ok: function () {     var that = this;     if (!that.data.hasDraw) {       return app.Tips({         title: "您还未签名"       })     };          var context1 = that.data.context1;       context1.draw(true, wx.canvasToTempFilePath({         canvasId: 'handWriting1',         success(res) {           console.log("res:", res)           console.log(res.tempFilePath) //得到了图片下面自己写上传吧           let Url = getApp().globalData.url,             header = HEADER;           console.log("Url:", Url)           if (getApp().globalData.token) header[TOKENNAME] = 'Bearer ' + getApp().globalData.token;           wx.uploadFile({             url: Url + "/api/task/upload/contract",             filePath: res.tempFilePath,             name: "file",             formData: {               file: "image",               key: that.data.orderKey             },             header: {               "Content-Type": "multipart/form-data",               [TOKENNAME]: 'Bearer ' + getApp().globalData.token             },             success: function (result) {               console.log(result)               var data = JSON.parse(result.data)               if (data.status == 200) {                 app.Tips({                   title: data.msg                 });                 setTimeout(function () {                   wx.redirectTo({                     url: '/pages/shouerlige/taskOrder_pay/index?key=' + that.data.orderKey + "&taskid=" + that.data.optionsTaskid,                   })                 }, 1200)               }else{                  return app.Tips({title:data.msg})               }             },             fail:function(err){             }           })         }       }))   },