Hbuilder-在线签名

不念不忘少年蓝@ 2022-09-15 03:29 172阅读 0赞

![watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA5bCP5bGB5a2p5aSn5biFLeadqOWwkeW5sw_size_8_color_FFFFFF_t_70_g_se_x_16][]

<template>
    	<view>
    		<view class="wrapper">
    			<view class="handBtn">
    				<image @click="selectColorEvent('black','#1A1A1A')" :src="selectColor === 'black' ? '../static/other/color_black_selected.png' : '../static/other/color_black.png'"
    				 :class="[selectColor === 'black' ? 'color_select' : '', 'black-select']"></image>
    				<image @click="selectColorEvent('red','#ca262a')" :src="selectColor === 'red' ? '../static/other/color_red_selected.png' : '../static/other/color_red.png'"
    				 :class="[selectColor === 'red' ? 'color_select' : '', 'black-select']"></image>
    				<button @click="retDraw" class="delBtn">重写</button>
    				<button @click="saveCanvasAsImg" class="saveBtn">保存</button>
    				<button @click="previewCanvasImg" class="previewBtn">预览</button>
    				<button @click="uploadCanvasImg" class="uploadBtn">上传</button>
    				<button @click="subCanvas" class="subBtn">完成</button>
    			</view>
    			<view class="handCenter">
    				<canvas class="handWriting" :disable-scroll="true" @touchstart="uploadScaleStart" @touchmove="uploadScaleMove"
    				 @touchend="uploadScaleEnd" canvas-id="handWriting"></canvas>
    			</view>
    			<view class="handRight">
    				<view class="handTitle">请签名</view>
    			</view>
    		</view>
    	</view>
    </template>
    
    <script>
    	export default {
    		data() {
    			return {
    				canvasName: 'handWriting',
    				ctx: '',
    				canvasWidth: 0,
    				canvasHeight: 0,
    				transparent: 1, // 透明度
    				selectColor: 'black',
    				lineColor: '#1A1A1A', // 颜色
    				lineSize: 1.5, // 笔记倍数
    				lineMin: 0.5, // 最小笔画半径
    				lineMax: 4, // 最大笔画半径
    				pressure: 1, // 默认压力
    				smoothness: 60, //顺滑度，用60的距离来计算速度
    				currentPoint: {},
    				currentLine: [], // 当前线条
    				firstTouch: true, // 第一次触发
    				radius: 1, //画圆的半径
    				cutArea: {
    					top: 0,
    					right: 0,
    					bottom: 0,
    					left: 0
    				}, //裁剪区域
    				bethelPoint: [], //保存所有线条 生成的贝塞尔点；
    				lastPoint: 0,
    				chirography: [], //笔迹
    				currentChirography: {}, //当前笔迹
    				linePrack: [] //划线轨迹 , 生成线条的实际点
    			};
    		},
    		onLoad() {
    			let canvasName = this.canvasName;
    			let ctx = wx.createCanvasContext(canvasName);
    
    			this.ctx = ctx;
    			var query = wx.createSelectorQuery();
    			query
    				.select('.handCenter')
    				.boundingClientRect(rect => {
    					this.canvasWidth = rect.width;
    					this.canvasHeight = rect.height;
    
    					/* 将canvas背景设置为 白底，不设置  导出的canvas的背景为透明 */
    					this.setCanvasBg('#fff');
    				})
    				.exec();
    		},
    		methods: {
    			// 笔迹开始
    			uploadScaleStart(e) {
    				if (e.type != 'touchstart') return false;
    				let ctx = this.ctx;
    				ctx.setFillStyle(this.lineColor); // 初始线条设置颜色
    				ctx.setGlobalAlpha(this.transparent); // 设置半透明
    				let currentPoint = {
    					x: e.touches[0].x,
    					y: e.touches[0].y
    				};
    				let currentLine = this.currentLine;
    				currentLine.unshift({
    					time: new Date().getTime(),
    					dis: 0,
    					x: currentPoint.x,
    					y: currentPoint.y
    				});
    				this.currentPoint = currentPoint;
    				// currentLine
    				if (this.firstTouch) {
    					this.cutArea = {
    						top: currentPoint.y,
    						right: currentPoint.x,
    						bottom: currentPoint.y,
    						left: currentPoint.x
    					};
    					this.firstTouch = false;
    				}
    				this.pointToLine(currentLine);
    			},
    			// 笔迹移动
    			uploadScaleMove(e) {
    				if (e.type != 'touchmove') return false;
    				if (e.cancelable) {
    					// 判断默认行为是否已经被禁用
    					if (!e.defaultPrevented) {
    						e.preventDefault();
    					}
    				}
    				let point = {
    					x: e.touches[0].x,
    					y: e.touches[0].y
    				};
    
    				//测试裁剪
    				if (point.y < this.cutArea.top) {
    					this.cutArea.top = point.y;
    				}
    				if (point.y < 0) this.cutArea.top = 0;
    
    				if (point.x > this.cutArea.right) {
    					this.cutArea.right = point.x;
    				}
    				if (this.canvasWidth - point.x <= 0) {
    					this.cutArea.right = this.canvasWidth;
    				}
    				if (point.y > this.cutArea.bottom) {
    					this.cutArea.bottom = point.y;
    				}
    				if (this.canvasHeight - point.y <= 0) {
    					this.cutArea.bottom = this.canvasHeight;
    				}
    				if (point.x < this.cutArea.left) {
    					this.cutArea.left = point.x;
    				}
    				if (point.x < 0) this.cutArea.left = 0;
    
    				this.lastPoint = this.currentPoint;
    				this.currentPoint = point;
    
    				let currentLine = this.currentLine;
    				currentLine.unshift({
    					time: new Date().getTime(),
    					dis: this.distance(this.currentPoint, this.lastPoint),
    					x: point.x,
    					y: point.y
    				});
    
    				this.pointToLine(currentLine);
    			},
    			// 笔迹结束
    			uploadScaleEnd(e) {
    				if (e.type != 'touchend') return 0;
    				let point = {
    					x: e.changedTouches[0].x,
    					y: e.changedTouches[0].y
    				};
    				this.lastPoint = this.currentPoint;
    				this.currentPoint = point;
    
    				let currentLine = this.currentLine;
    				currentLine.unshift({
    					time: new Date().getTime(),
    					dis: this.distance(this.currentPoint, this.lastPoint),
    					x: point.x,
    					y: point.y
    				});
    
    				if (currentLine.length > 2) {
    					var info = (currentLine[0].time - currentLine[currentLine.length - 1].time) / currentLine.length;
    					//$("#info").text(info.toFixed(2));
    				}
    				//一笔结束，保存笔迹的坐标点，清空，当前笔迹
    				//增加判断是否在手写区域；
    				this.pointToLine(currentLine);
    				var currentChirography = {
    					lineSize: this.lineSize,
    					lineColor: this.lineColor
    				};
    				var chirography = this.chirography;
    				chirography.unshift(currentChirography);
    				this.chirography = chirography;
    
    				var linePrack = this.linePrack;
    				linePrack.unshift(this.currentLine);
    				this.linePrack = linePrack;
    				this.currentLine = [];
    			},
    			retDraw() {
    				this.ctx.clearRect(0, 0, 700, 730);
    				this.ctx.draw();
    
    				//设置canvas背景
    				this.setCanvasBg('#fff');
    			},
    			//画两点之间的线条；参数为:line，会绘制最近的开始的两个点；
    			pointToLine(line) {
    				this.calcBethelLine(line);
    				return;
    			},
    			//计算插值的方式；
    			calcBethelLine(line) {
    				if (line.length <= 1) {
    					line[0].r = this.radius;
    					return;
    				}
    				let x0,
    					x1,
    					x2,
    					y0,
    					y1,
    					y2,
    					r0,
    					r1,
    					r2,
    					len,
    					lastRadius,
    					dis = 0,
    					time = 0,
    					curveValue = 0.5;
    				if (line.length <= 2) {
    					x0 = line[1].x;
    					y0 = line[1].y;
    					x2 = line[1].x + (line[0].x - line[1].x) * curveValue;
    					y2 = line[1].y + (line[0].y - line[1].y) * curveValue;
    					//x2 = line[1].x;
    					//y2 = line[1].y;
    					x1 = x0 + (x2 - x0) * curveValue;
    					y1 = y0 + (y2 - y0) * curveValue;
    				} else {
    					x0 = line[2].x + (line[1].x - line[2].x) * curveValue;
    					y0 = line[2].y + (line[1].y - line[2].y) * curveValue;
    					x1 = line[1].x;
    					y1 = line[1].y;
    					x2 = x1 + (line[0].x - x1) * curveValue;
    					y2 = y1 + (line[0].y - y1) * curveValue;
    				}
    				//从计算公式看，三个点分别是(x0,y0),(x1,y1),(x2,y2) ；(x1,y1)这个是控制点，控制点不会落在曲线上；实际上，这个点还会手写获取的实际点，却落在曲线上
    				len = this.distance({
    					x: x2,
    					y: y2
    				}, {
    					x: x0,
    					y: y0
    				});
    				lastRadius = this.radius;
    				for (let n = 0; n < line.length - 1; n++) {
    					dis += line[n].dis;
    					time += line[n].time - line[n + 1].time;
    					if (dis > this.smoothness) break;
    				}
    
    				this.radius = Math.min((time / len) * this.pressure + this.lineMin, this.lineMax) * this.lineSize;
    				line[0].r = this.radius;
    				//计算笔迹半径；
    				if (line.length <= 2) {
    					r0 = (lastRadius + this.radius) / 2;
    					r1 = r0;
    					r2 = r1;
    					//return;
    				} else {
    					r0 = (line[2].r + line[1].r) / 2;
    					r1 = line[1].r;
    					r2 = (line[1].r + line[0].r) / 2;
    				}
    				let n = 5;
    				let point = [];
    				for (let i = 0; i < n; i++) {
    					let t = i / (n - 1);
    					let x = (1 - t) * (1 - t) * x0 + 2 * t * (1 - t) * x1 + t * t * x2;
    					let y = (1 - t) * (1 - t) * y0 + 2 * t * (1 - t) * y1 + t * t * y2;
    					let r = lastRadius + ((this.radius - lastRadius) / n) * i;
    					point.push({
    						x: x,
    						y: y,
    						r: r
    					});
    					if (point.length == 3) {
    						let a = this.ctaCalc(point[0].x, point[0].y, point[0].r, point[1].x, point[1].y, point[1].r, point[2].x, point[2]
    							.y, point[2].r);
    						a[0].color = this.lineColor;
    						// let bethelPoint = this.bethelPoint;
    						// bethelPoint = bethelPoint.push(a);
    						this.bethelDraw(a, 1);
    						point = [{
    							x: x,
    							y: y,
    							r: r
    						}];
    					}
    				}
    				this.currentLine = line;
    			},
    			//求两点之间距离
    			distance(a, b) {
    				let x = b.x - a.x;
    				let y = b.y - a.y;
    				return Math.sqrt(x * x + y * y);
    			},
    			ctaCalc(x0, y0, r0, x1, y1, r1, x2, y2, r2) {
    				let a = [],
    					vx01,
    					vy01,
    					norm,
    					n_x0,
    					n_y0,
    					vx21,
    					vy21,
    					n_x2,
    					n_y2;
    				vx01 = x1 - x0;
    				vy01 = y1 - y0;
    				norm = Math.sqrt(vx01 * vx01 + vy01 * vy01 + 0.0001) * 2;
    				vx01 = (vx01 / norm) * r0;
    				vy01 = (vy01 / norm) * r0;
    				n_x0 = vy01;
    				n_y0 = -vx01;
    				vx21 = x1 - x2;
    				vy21 = y1 - y2;
    				norm = Math.sqrt(vx21 * vx21 + vy21 * vy21 + 0.0001) * 2;
    				vx21 = (vx21 / norm) * r2;
    				vy21 = (vy21 / norm) * r2;
    				n_x2 = -vy21;
    				n_y2 = vx21;
    				a.push({
    					mx: x0 + n_x0,
    					my: y0 + n_y0,
    					color: '#1A1A1A'
    				});
    				a.push({
    					c1x: x1 + n_x0,
    					c1y: y1 + n_y0,
    					c2x: x1 + n_x2,
    					c2y: y1 + n_y2,
    					ex: x2 + n_x2,
    					ey: y2 + n_y2
    				});
    				a.push({
    					c1x: x2 + n_x2 - vx21,
    					c1y: y2 + n_y2 - vy21,
    					c2x: x2 - n_x2 - vx21,
    					c2y: y2 - n_y2 - vy21,
    					ex: x2 - n_x2,
    					ey: y2 - n_y2
    				});
    				a.push({
    					c1x: x1 - n_x2,
    					c1y: y1 - n_y2,
    					c2x: x1 - n_x0,
    					c2y: y1 - n_y0,
    					ex: x0 - n_x0,
    					ey: y0 - n_y0
    				});
    				a.push({
    					c1x: x0 - n_x0 - vx01,
    					c1y: y0 - n_y0 - vy01,
    					c2x: x0 + n_x0 - vx01,
    					c2y: y0 + n_y0 - vy01,
    					ex: x0 + n_x0,
    					ey: y0 + n_y0
    				});
    				a[0].mx = a[0].mx.toFixed(1);
    				a[0].mx = parseFloat(a[0].mx);
    				a[0].my = a[0].my.toFixed(1);
    				a[0].my = parseFloat(a[0].my);
    				for (let i = 1; i < a.length; i++) {
    					a[i].c1x = a[i].c1x.toFixed(1);
    					a[i].c1x = parseFloat(a[i].c1x);
    					a[i].c1y = a[i].c1y.toFixed(1);
    					a[i].c1y = parseFloat(a[i].c1y);
    					a[i].c2x = a[i].c2x.toFixed(1);
    					a[i].c2x = parseFloat(a[i].c2x);
    					a[i].c2y = a[i].c2y.toFixed(1);
    					a[i].c2y = parseFloat(a[i].c2y);
    					a[i].ex = a[i].ex.toFixed(1);
    					a[i].ex = parseFloat(a[i].ex);
    					a[i].ey = a[i].ey.toFixed(1);
    					a[i].ey = parseFloat(a[i].ey);
    				}
    				return a;
    			},
    			bethelDraw(point, is_fill, color) {
    				let ctx = this.ctx;
    				ctx.beginPath();
    				ctx.moveTo(point[0].mx, point[0].my);
    				if (undefined != color) {
    					ctx.setFillStyle(color);
    					ctx.setStrokeStyle(color);
    				} else {
    					ctx.setFillStyle(point[0].color);
    					ctx.setStrokeStyle(point[0].color);
    				}
    				for (let i = 1; i < point.length; i++) {
    					ctx.bezierCurveTo(point[i].c1x, point[i].c1y, point[i].c2x, point[i].c2y, point[i].ex, point[i].ey);
    				}
    				ctx.stroke();
    				if (undefined != is_fill) {
    					ctx.fill(); //填充图形 ( 后绘制的图形会覆盖前面的图形, 绘制时注意先后顺序 )
    				}
    				ctx.draw(true);
    			},
    			selectColorEvent(str, color) {
    				this.selectColor = str;
    				this.lineColor = color;
    			},
    			//将Canvas内容转成 临时图片 --> cb 为回调函数 形参 tempImgPath 为 生成的图片临时路径
    			canvasToImg(cb) {
    				//这种写法移动端 出不来
    
    				this.ctx.draw(true, () => {
    					wx.canvasToTempFilePath({
    						canvasId: 'handWriting',
    						fileType: 'png',
    						quality: 1, //图片质量
    						success(res) {
    							// console.log(res.tempFilePath, 'canvas生成图片地址');
    
    							wx.showToast({
    								title: '执行了吗？'
    							});
    
    							cb(res.tempFilePath);
    						}
    					});
    				});
    			},
    			//完成
    			subCanvas() {
    				this.ctx.draw(true, () => {
    					wx.canvasToTempFilePath({
    						canvasId: 'handWriting',
    						fileType: 'png',
    						quality: 1, //图片质量
    						success(res) {
    							// console.log(res.tempFilePath, 'canvas生成图片地址');
    							wx.showToast({
    								title: '以保存'
    							});
    							//保存到系统相册
    							wx.saveImageToPhotosAlbum({
    								filePath: res.tempFilePath,
    								success(res) {
    									wx.showToast({
    										title: '已成功保存到相册',
    										duration: 2000
    									});
    								}
    							});
    						}
    					});
    				});
    			},
    			//保存到相册
    			saveCanvasAsImg() {
    
    				/*
    				this.canvasToImg( tempImgPath=>{
    					// console.log(tempImgPath, '临时路径');
    					wx.saveImageToPhotosAlbum({
    						filePath: tempImgPath,
    						success(res) {
    							wx.showToast({
    								title: '已保存到相册',
    								duration: 2000
    							});
    						}
    					})
    				} );
    		*/
    
    				wx.canvasToTempFilePath({
    					canvasId: 'handWriting',
    					fileType: 'png',
    					quality: 1, //图片质量
    					success(res) {
    						// console.log(res.tempFilePath, 'canvas生成图片地址');
    						wx.saveImageToPhotosAlbum({
    							filePath: res.tempFilePath,
    							success(res) {
    								wx.showToast({
    									title: '已保存到相册',
    									duration: 2000
    								});
    							}
    						});
    					}
    				});
    			},
    			//预览
    			previewCanvasImg() {
    				wx.canvasToTempFilePath({
    					canvasId: 'handWriting',
    					fileType: 'jpg',
    					quality: 1, //图片质量
    					success(res) {
    						// console.log(res.tempFilePath, 'canvas生成图片地址');
    
    						wx.previewImage({
    							urls: [res.tempFilePath] //预览图片 数组
    						});
    					}
    				});
    
    				/*	//移动端出不来  ^~^！！
    						this.canvasToImg( tempImgPath=>{
    							wx.previewImage({
    								urls: [tempImgPath], //预览图片 数组
    							})
    						} );
    				*/
    			},
    			//上传
    			uploadCanvasImg() {
    
    				wx.canvasToTempFilePath({
    					canvasId: 'handWriting',
    					fileType: 'png',
    					quality: 1, //图片质量
    					success(res) {
    						// console.log(res.tempFilePath, 'canvas生成图片地址');
    
    						//上传
    						wx.uploadFile({
    							url: 'https://example.weixin.qq.com/upload', // 仅为示例，非真实的接口地址
    							filePath: res.tempFilePath,
    							name: 'file_signature',
    							formData: {
    								user: 'test'
    							},
    							success(res) {
    								const data = res.data;
    								// do something
    							}
    						});
    					}
    				});
    			},
    			//设置canvas背景色  不设置  导出的canvas的背景为透明
    			//@params：字符串  color
    			setCanvasBg(color) {
    
    				/* 将canvas背景设置为 白底，不设置  导出的canvas的背景为透明 */
    				//rect() 参数说明  矩形路径左上角的横坐标，左上角的纵坐标, 矩形路径的宽度, 矩形路径的高度
    				//这里是 canvasHeight - 4 是因为下边盖住边框了，所以手动减了写
    				this.ctx.rect(0, 0, this.canvasWidth, this.canvasHeight - 4);
    				// ctx.setFillStyle('red')
    				this.ctx.setFillStyle(color);
    				this.ctx.fill(); //设置填充
    				this.ctx.draw(); //开画
    			}
    		}
    	};
    </script>
    
    <style>
    	page {
    		background: #fbfbfb;
    		height: auto;
    		overflow: hidden;
    	}
    
    	.wrapper {
    		width: 100%;
    		height: 95vh;
    		margin: 30rpx 0;
    		overflow: hidden;
    		display: flex;
    		align-content: center;
    		flex-direction: row;
    		justify-content: center;
    		font-size: 28rpx;
    	}
    
    	.handWriting {
    		background: #fff;
    		width: 100%;
    		height: 95vh;
    	}
    
    	.handRight {
    		display: inline-flex;
    		align-items: center;
    	}
    
    	.handCenter {
    		border: 4rpx dashed #e9e9e9;
    		flex: 5;
    		overflow: hidden;
    		box-sizing: border-box;
    	}
    
    	.handTitle {
    		transform: rotate(90deg);
    		flex: 1;
    		color: #666;
    	}
    
    	.handBtn button {
    		font-size: 28rpx;
    	}
    
    	.handBtn {
    		height: 95vh;
    		display: inline-flex;
    		flex-direction: column;
    		justify-content: space-between;
    		align-content: space-between;
    		flex: 1;
    	}
    
    	.delBtn {
    		position: absolute;
    		top: 250rpx;
    		left: 0rpx;
    		transform: rotate(90deg);
    		color: #666;
    	}
    
    	.delBtn image {
    		position: absolute;
    		top: 13rpx;
    		left: 25rpx;
    	}
    
    	.subBtn {
    		position: absolute;
    		bottom: 52rpx;
    		left: -3rpx;
    		display: inline-flex;
    		transform: rotate(90deg);
    		background: #008ef6;
    		color: #fff;
    		margin-bottom: 30rpx;
    		text-align: center;
    		justify-content: center;
    	}
    
    	/*Peach - 新增 - 保存*/
    
    	.saveBtn {
    		position: absolute;
    		top: 375rpx;
    		left: 0rpx;
    		transform: rotate(90deg);
    		color: #666;
    	}
    
    	.previewBtn {
    		position: absolute;
    		top: 500rpx;
    		left: 0rpx;
    		transform: rotate(90deg);
    		color: #666;
    	}
    
    	.uploadBtn {
    		position: absolute;
    		top: 625rpx;
    		left: 0rpx;
    		transform: rotate(90deg);
    		color: #666;
    	}
    
    	/*Peach - 新增 - 保存*/
    
    	.black-select {
    		width: 60rpx;
    		height: 60rpx;
    		position: absolute;
    		top: 30rpx;
    		left: 25rpx;
    	}
    
    	.black-select.color_select {
    		width: 90rpx;
    		height: 90rpx;
    		top: 100rpx;
    		left: 10rpx;
    	}
    
    	.red-select {
    		width: 60rpx;
    		height: 60rpx;
    		position: absolute;
    		top: 140rpx;
    		left: 25rpx;
    	}
    
    	.red-select.color_select {
    		width: 90rpx;
    		height: 90rpx;
    		top: 120rpx;
    		left: 10rpx;
    	}
    </style>

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