微信小程序在线签名（可上传，可转base64，两种方法都有）

Page({   data: {     context1: null,     hasDraw:false, //默认没有画     src:null, test:"",   },   onLoad: function() {     var context1 = wx.createCanvasContext('handWriting1');     context1.setStrokeStyle("#000000")     context1.setLineWidth(3);     this.setData({       context1: context1,     })   },   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){       console.log("签字是空白的 没有签字")     }else{       var context1 = that.data.context1;       context1.draw(true, wx.canvasToTempFilePath({         canvasId: 'handWriting1',         success(res) {           console.log(res.tempFilePath) //得到了图片下面自己写上传吧           that.setData({             src: res.tempFilePath           }) that.getBase64Image(that.data.src);                    }       }))     }   }, //转换图片为base64函数 getBase64Image(img) { let that=this; wx.getFileSystemManager().readFile({ filePath: img, //选择图片返回的相对路径 encoding: "base64", //这个是很重要的 success: res => { //成功的回调 //返回base64格式 var base64Str = 'data:image/' + 'jpeg' + ';base64,' + res.data console.log(base64Str); that.setData({test:base64Str}); }, fail: err => { console.log(err) reject(err) } }) }, });