pad-app/pages/quality/zsEdit.vue

<template>
	<view class="sign">
		<head-view title="绘制质损图"></head-view>
		<view class="containe contentFixedr">
			<view class="sign-box">

				<canvas class="mycanvas" canvas-id="mycanvas" @touchstart="touchstart" @touchmove="touchmove"
					@touchend="touchend" disable-scroll="true"></canvas>
				<view class="canvasBg">
					<image :src="imgUrl" mode=""></image>
				</view>
			</view>
			<view class="sigh-btns">
				<view class="btn qx" @click="handleCancel">取消</view>
				<view class="btn qc" @click="handleReset">清除</view>
				<view class="btn bc" @click="handleConfirm">保存</view>
			</view>
		</view>
	</view>
</template>
<script>
	import {
		pathToBase64,
		base64ToPath
	} from '../../js_sdk/mmmm-image-tools/index.js'
	import utils from '@/common/util.js';
	var x = 20;
	var y = 20;
	var tempPoint = []; //用来存放当前画纸上的轨迹点
	var id = 0;
	var type = '';
	let that;
	export default {
		data() {
			return {
				ctx: '', //绘图图像
				points: [], //路径点集合,
				width: 0,
				height: 0,
				loginObj: {},
				signImg: "",
				url: "",
				imgUrl: "",
				ytImg: "",
				isSign: false,
			};
		},
		onLoad(options) {
			if ('params' in options) {
				// 获取传递的对象参数，使用decodeURIComponent解码，并转为对象
				this.imgUrl = JSON.parse(decodeURIComponent(options.params)).imgUrl
			}
			this.loginObj = uni.getStorageSync('loginObj')
			if (this.imgUrl == "") {
				this.handleReset()
			} else {
				this.initImg(this.imgUrl)
			}
		},
		methods: {
			initImg(name) {
				uni.request({
					url: `${this.$local}/api/file/url/?fileName=${name}`,
					header: {
						'Content-Type': 'application/json', //自定义请求头信息
						'Authorization': `Bearer ${this.loginObj.access_token}`
					},
					method: 'GET', //请求方式，必须为大写
					success: (res) => {
						if (res.statusCode == 200) {
							this.imgUrl = res.data
							this.init()
						}
					}
				})
			},
			init() {
				let that = this
				that.ctx = uni.createCanvasContext('mycanvas', that); //创建绘图对象
				//设置画笔样式
				that.ctx.lineWidth = 4;
				that.ctx.lineCap = 'round';
				that.ctx.lineJoin = 'round';
				uni.getImageInfo({
					src: that.imgUrl,
					success(res1) {
						//填充白色背景图片
						that.ctx.drawImage(that.imgUrl, 0, 0, 624, 224);
					},
					fail(res) {
						console.log(res);
					}
				});
			},
			//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 / 1.75,
					Y: startY / 1.75
				};

				/* **************************************************
				    #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);
				this.isSign = true

				//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 / 1.75,
					Y: moveY / 1.75
				};
				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.strokeStyle = 'red';
				this.ctx.lineWidth = 2;
				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() {
				var that = this
				that.points = []
				uni.request({
					url: `${that.$local}/api/miniapp/typeRef/domain/REFERENCE_DIAGRAM`,
					header: {
						'Content-Type': 'application/json', //自定义请求头信息
						'Authorization': `Bearer ${that.loginObj.access_token}`
					},
					method: 'GET', //请求方式，必须为大写
					success: (res) => {
						if (res.statusCode == 200) {
							that.initImg(res.data.data[0].ptrDesc)
							this.ytImg = res.data.data[0].ptrDesc
							this.isSign = false
						}
					}
				})
				// that.ctx.clearRect(0, 0, 624, 224);
				// 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() {
				let that = this
				uni.canvasToTempFilePath({
					canvasId: 'mycanvas',
					success: function(e) {
						const myPromise = new Promise((resolve, reject) => {
							// 执行异步操作
							// 当操作完成时调用resolve()或reject()
							pathToBase64(e.tempFilePath).then(path => {
									that.url = path
									if (that.isSign) {
										uni.setStorageSync('hzzsImg', that.url)
									} else {
										uni.setStorageSync('hzzsImg', that.ytImg)
									}
									uni.setStorageSync('isSign', that.isSign)
									uni.navigateBack({
										delta: 1
									});
								})
								.catch(error => {
									console.error(error)
								})
						});
					}
				});
			}
		}
	};
</script>

<style lang="scss" scoped>
	.container {
		height: calc(100vh - 68px);
		padding-bottom: 30px;
		background-color: #fff;
	}

	.sign-box {
		display: flex;
		justify-content: center;
		position: relative;
		margin-top: 48px;
	}

	.sign-view {
		height: 100%;
	}

	.sigh-btns {
		display: flex;
		justify-content: center;
		width: 100%;
		height: 80px;
		background: #FFFFFF;
		box-shadow: 0 -3px 7px 0 rgba(0, 0, 0, 0.10);
		position: fixed;
		bottom: 0;
	}

	.btn {
		margin: 15.5px 17px;
		width: 200px;
		height: 49px;
		border-radius: 2px;
		font-size: 18px;
		text-align: center;
		line-height: 49px;
	}

	.qx {
		background-color: #eee;
	}

	.qc {
		color: #0067CF;
		background-color: rgba(0, 103, 207, 0.10);
	}

	.bc {
		color: #fff;
		background: #0067CF;
	}

	.mycanvas {
		margin: auto 0rpx;
		background-color: transparent;
		margin-top: 130px;
		width: 624px;
		height: 224px;
		z-index: 999;
		transform: scale(1.75)
	}

	.canvasBg {
		width: 624px;
		height: 224px;
		position: absolute;
		top: 130px;
		transform: scale(1.75)
	}

	.canvsborder {
		border: 1rpx solid #333;
		position: fixed;
		top: 0;
		left: 10000rpx;
	}
</style>