博客

<template>
<view class="container">
  <view class="content-box">
      <div class="button" @tap="initCanvas" v-show="!showCanvas">签名</div>
      <image :src="imgRrl" v-if="imgShow" alt="" style="position: fixed;top: 350px;"></image>
      <div v-show="showCanvas">
          <canvas canvas-id="canvasid" class="canvasid" disable-scroll="true" @touchstart="ontouchstart"
              @touchmove="touchmove" @touchend="touchend"></canvas>
          <view class="footer">
              <view class="left" @click="uploadPic">保存</view>
              <view class="right" @click="clear">清除</view>
              <view class="right" style="background-color: coral;" @click="look">预览</view>
              <view class="close" @click="close">关闭</view>
          </view>
      </div>

  </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
export default {
  data() {
      return {
          headerStyleHeight: 0,
          headerStyleTop: 0,
          oc: "",
          imgRrl: 'https://file.iviewui.com/weapp/dist/e5da9fdc97a0b3fb16c115d379820583.jpg',
          imgShow: false,
          points: [], //路径点集合 
          showCanvas: false, //
      };
  },

  methods: {
      close: function() {
          this.showCanvas = false;
          this.clear();
      },
      initCanvas() {
          this.showCanvas = true;
          this.oc = uni.createCanvasContext('canvasid');
          console.log(this.oc);
          //设置画笔样式
          this.oc.lineWidth = 4;
          this.oc.lineCap = "round";
          this.oc.lineJoin = "round";
          // this.oc.setStrokeStyle("#ffffff");

      },
      ontouchend(e) {
          oc.ontouchmove = null;
      },
      ontouchmove(e) {
          const {
              clientX,
              clientY
          } = e.changedTouches[0];
          oc.lineTo(clientX - oc.offsetLeft, clientY - oc.offsetTop);
          oc.stroke();
      },
      //触摸开始，获取到起点

      ontouchstart(e) {
          // debugger
          //   ctx.beginPath();
          const startX = e.changedTouches[0].x;
          const startY = e.changedTouches[0].y;
          //   let startX = e.changedTouches[0].x;
          //   let startY = e.changedTouches[0].y;
          //   debugger
          let startPoint = {
              X: startX,
              Y: startY
          };
          this.points.push(startPoint);
          //每次触摸开始，开启新的路径
          this.oc.beginPath();
      },
      //触摸移动，获取到路径点
      touchmove(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() {
          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() {
          let point1 = this.points[0]
          let point2 = this.points[1]
          this.points.shift()
          this.oc.moveTo(point1.X, point1.Y)
          this.oc.lineTo(point2.X, point2.Y)
          this.oc.stroke()
          this.oc.draw(true)
      },
      //清空画布
      clear() {
          let that = this;
          uni.getSystemInfo({
              success: function(res) {
                  let canvasw = res.windowWidth;
                  let canvash = res.windowHeight;
                  that.oc.clearRect(0, 0, canvasw, canvash);
                  that.oc.draw(true);
              },
          })
          tempPoint = [];
          that.imgRrl = ''
      },
      //预览图片
      look() {
          let that = this
          if (tempPoint.length == 0) {
              uni.showToast({
                  title: '请先签名',
                  icon: 'none',
                  duration: 2000
              });
              return;
          }
          uni.canvasToTempFilePath({
              canvasId: 'canvasid',
              success: function(res) {
                  console.log('look', res)
                  that.imgRrl = res.tempFilePath;
                  that.imgShow = true;
                  //console.log('imgRrl', that.imgRrl)
              }
          })
      },
      //上传签名到服务器
      uploadPic() {
          let that = this;
          if (tempPoint.length == 0) {
              uni.showToast({
                  title: '请先签名',
                  icon: 'none',
                  duration: 2000
              });
              return;
          }
          uni.canvasToTempFilePath({
              canvasId: 'canvasid',
              fileType: 'png',
              quality: 1, //图片质量
              success(res) {
                  uni.uploadFile({
                      url: 'https://www.firstknow.club:8082/api/values/UploadSign', //后端接口地址  
                      name: 'file', //必填 , 此为类型名称
                      filePath: res.tempFilePath,//电子签名图片路径
                      success: (res) => { //上传成功后逻辑
                          uni.showToast({
                              title: '签名成功!'
                          });
                      },
                      fail: (err) => {
                          console.log(err);
                          uni.showToast({
                              title: '签名失败!'
                          });
                      }
                  });
              }
          });
      }
  }
};
</script>

<style lang="scss">
.button {
  width: 100%;
  height: 50px;
  line-height: 50px;
  text-align: center;
  font-size: 20px;
  border: 1px solid #bbbbbb;
}

.header-box {
  width: 100%;
  background-color: #ffffff;
  padding-bottom: 20rpx;
  color: red;
}

.content-box {
  width: 100%;
  height: 500px;
  //   background-color: aliceblue;
  padding: 20rpx;
  box-sizing: border-box;
}

.signature {
  position: fixed;
  top: 10px;
  left: 2%;
  z-index: 999;
  width: 96%;
}

page {
  background: #fff;
}

.container {

  padding: 20rpx 0 120rpx 0;
  box-sizing: border-box;
}

.title {
  height: 50upx;
  line-height: 50upx;
  font-size: 16px;
}

.mycanvas {
  width: 100%;
  // height: calc(100vh - 200upx);
  height: 300px;
  background-color: aliceblue;
}

.footer {
  font-size: 14px;
  height: 150upx;
  display: flex;
  justify-content: space-around;
  align-items: center;
}

.left,
.right,
.close {
  line-height: 100upx;
  height: 100upx;
  width: 220upx;
  text-align: center;
  font-weight: bold;
  color: white;
  border-radius: 5upx;
}

.left {
  background: #007AFF;
}

.right {
  background: orange;
}

.close {
  background: #A3A3A3;
}
</style>