Small program handwritten signature function

<template>
  <view class="container">
    <view class="sign-box">
      <canvas class="mycanvas"
              :style="{width:width +'px',height:height +'px'}"
              canvas-id="mycanvas"
              @touchstart="touchstart"
              @touchmove="touchmove"
              @touchend="touchend"></canvas>
      <canvas canvas-id="camCacnvs"
            :style="{width:height +'px',height:width +'px'}"
             class="canvsborder"></canvas>
    </view>
   <view class="sign-btns">
      <button class="btn"
              @tap="handleCancel">返回</button>
      <button class="btn"
              @tap="handleReset">重写</button>
      <button class="btn"
              @tap="handleConfirm">完成</button>
    </view>
  </view>

</template>
<script>
var x = 20;
var y = 20;
var tempPoint = []; //用来存放当前画纸上的轨迹点
let that;
export default {
    
    
  data() {
    
    
    return {
    
    
      ctx: '', //绘图图像
      points: [], //路径点集合,
      width: 0,
      height: 0
    };
  },
  mounted() {
    
    },

  onLoad(option) {
    
    
    that = this;
    this.ctx = uni.createCanvasContext('mycanvas', this); //创建绘图对象
    //设置画笔样式
    this.ctx.lineWidth = 4;
    this.ctx.lineCap = 'round';
    this.ctx.lineJoin = 'round';

    uni.getSystemInfo({
    
    
      success: function (res) {
    
    
        console.log(58,res);
        that.width = res.windowWidth;
        that.height = res.windowHeight * 0.9;
      }
    });
  },

  methods: {
    
    
    //触摸开始，获取到起点
    touchstart: function (e) {
    
    
      let startX = e.changedTouches[0].x;
      let startY = e.changedTouches[0].y;
      let startPoint = {
    
    
        X: startX,
        Y: startY
      };

      /* **************************************************
				    #由于uni对canvas的实现有所不同，这里需要把起点存起来
				 * **************************************************/
      this.points.push(startPoint);

      //每次触摸开始，开启新的路径
      this.ctx.beginPath();
    },

    //触摸移动，获取到路径点
    touchmove: function (e) {
    
    
      let moveX = e.changedTouches[0].x;
      let moveY = e.changedTouches[0].y;
      let movePoint = {
    
    
        X: moveX,
        Y: moveY
      };
      this.points.push(movePoint); //存点
      let len = this.points.length;
      if (len >= 2) {
    
    
        this.draw(); //绘制路径
      }
      tempPoint.push(movePoint);
    },

    // 触摸结束，将未绘制的点清空防止对后续路径产生干扰
    touchend: function () {
    
    
      this.points = [];
    },

    /* ***********************************************
			#   绘制笔迹
			#   1.为保证笔迹实时显示，必须在移动的同时绘制笔迹
			#   2.为保证笔迹连续，每次从路径集合中区两个点作为起点（moveTo）和终点(lineTo)
			#   3.将上一次的终点作为下一次绘制的起点（即清除第一个点）
			************************************************ */
    draw: function () {
    
    
      let point1 = this.points[0];
      let point2 = this.points[1];
      this.points.shift();
      this.ctx.moveTo(point1.X, point1.Y);
      this.ctx.lineTo(point2.X, point2.Y);
      this.ctx.stroke();
      this.ctx.draw(true);
    },

    handleCancel() {
    
    
      uni.navigateBack({
    
    
        delta: 1
      });
    },

    //清空画布
    handleReset: function () {
    
    
      console.log('handleReset');
      that.ctx.clearRect(0, 0, that.width, that.height);
      that.ctx.draw(true);
      tempPoint = [];
    },

    //将签名笔迹上传到服务器，并将返回来的地址存到本地
    handleConfirm: function () {
    
    
      if (tempPoint.length == 0) {
    
    
        uni.showToast({
    
    
          title: '请先签名',
          icon: 'none',
          duration: 2000
        });
        return;
      }
      uni.canvasToTempFilePath({
    
    
        canvasId: 'mycanvas',
        success: function (res) {
    
    
          let tempPath = res.tempFilePath;
          console.log(149,res)
          const ctx = uni.createCanvasContext('camCacnvs', that);
          ctx.translate(0, that.width);
          ctx.rotate((-90 * Math.PI) / 180);
          ctx.drawImage(tempPath, 0, 0, that.width, that.height);
          ctx.draw();
          setTimeout(() => {
    
    
            uni.uploadFile({
    
    
                /* // 拿到临时图片路径后上传到服务器，服务器将返回一个公网地址，
                届时在任意角落都将能访问到这张图片 */
                filePath: tempPath, //临时文件路径
                url: 'https://xxxxxxxxxxx.com/api/upload/uploadImage',  //填写公司的服务器地址
                name: 'file',   /* //非常重要！！！！是后台访问二进制数据的关键
                该 file 是对应接口，所需要传递的参数 */
                timeout:5000,
                success(res2){
    
    
                    console.log(res2);
                }
            })
          }, 200);
        }
      });
    }
  }
};
</script>

<style lang="scss" scoped>
.container {
    
    
  display: flex;
  flex-direction: column;
  .sign-box {
    
    
    width: 100%;
    .mycanvas {
    
    
      width: 100%;
      margin: 0rpx;
      background-color: #ececec;
    }
    .canvsborder {
    
    
      border: 1rpx solid #333;
      position: fixed;
      top: 0;
      left: 10000rpx;
    }
  }

  .sign-btns {
    
    
    display: flex;
    flex-direction: row;
    .btn {
    
    
      box-sizing: border-box;
      font-size: 28rpx;
      padding: 5rpx;
      transform: rotate(90deg);
      border-radius: 10rpx;
    }
    .btn {
    
    

    }
  }
}
</style>