【uniapp 开发】手绘签名组件

• 代码如下：

<template>
	<view class="content">
		<button type="primary" @tap="doss">点击签名1</button>
		<button type="primary" @tap="doss2">点击签名2</button>

		<view class="imgs">
			<image class="img" :src="img1" mode="widthFix"></image>
			<image class="img" :src="img2" mode="widthFix"></image>
		</view>

		<catSignature canvasId="canvas1"  @close="close" @save="save" :visible="isShow" />
		<catSignature canvasId="canvas2" @close="close2" @save="save2" :visible="isShow2" />

	</view>
</template>

<script>
	import catSignature from "@/components/cat-signature/cat-signature.vue"
	export default {
		components:{catSignature},
		data() {
			return {
				img1:'',
				img2:'',
				isShow:false,
				isShow2:false,
			}
		},
		onLoad() {

		},
		methods: {
			doss(){
				this.isShow = true;
			},
			close(){
				this.isShow = false;
			},
			save(val){
				this.isShow = false;
				this.img1 = val
			},
			doss2(){
				this.isShow2 = true;
			},
			close2(){
				this.isShow2 = false;
			},
			save2(val){
				this.isShow2 = false;
				this.img2 = val
			},
		}
	}
</script>

<style>
	.imgs{width: 500upx;height: 500upx;display: flex;margin: 0 auto;flex-wrap: wrap;}
	.imgs img{width: 100%; height: 100%;}
</style>

• 插件代码：

<template>
	<view v-if="visibleSync" class="cat-signature" :class="{'visible':show}" @touchmove.stop.prevent="moveHandle">
		<view class="mask" @tap="close" />
		<view class="content">
			<canvas class='firstCanvas' :canvas-id="canvasId" @touchmove='move' @touchstart='start($event)' @touchend='end'
			 @touchcancel='cancel' @longtap='tap' disable-scroll='true' @error='error' />
			<view class="btns">
				<view class="btn" @tap="clear">清除</view>
				<view class="btn" @tap="save">保存</view>
			</view>
		</view>
	</view>
</template>

<script>
	var content = null;
	var touchs = [];
	var canvasw = 0;
	var canvash = 0;
	//获取系统信息
	uni.getSystemInfo({
		success: function(res) {
			canvasw = res.windowWidth;
			canvash = canvasw * 9 / 16;
		},
	})
	export default{
		name:'cat-signature',
		props:{
			visible: {
				type: Boolean,
				default: false
			},
			canvasId:{
				type: String,
				default: 'firstCanvas'
			}
		},
		data(){
			return{
				show:false,
				visibleSync: false,
				signImage:'',
				hasDh:false,
			}
		},
		watch:{
			visible(val) {
				this.visibleSync = val;
				this.show = val;
				this.getInfo()
			}
		},

		created(options) {
			this.visibleSync = this.visible
			this.getInfo()
			setTimeout(() => {
				this.show = this.visible;
			}, 100)
		},
		methods:{
			getInfo(){
				//获得Canvas的上下文
				content = uni.createCanvasContext(this.canvasId,this)
				//设置线的颜色
				content.setStrokeStyle("#000")
				//设置线的宽度
				content.setLineWidth(5)
				//设置线两端端点样式更加圆润
				content.setLineCap('round')
				//设置两条线连接处更加圆润
				content.setLineJoin('round')
			},
			//
			close() {
				this.show = false;
				this.hasDh = false;
				this.$emit('close')
			},
			moveHandle(){

			},
			// 画布的触摸移动开始手势响应
			start(e){
				let point = {
					x: e.touches[0].x,
					y: e.touches[0].y,
				}
				touchs.push(point);
				this.hasDh = true
			},
			// 画布的触摸移动手势响应
			move: function(e) {
				let point = {
					x: e.touches[0].x,
					y: e.touches[0].y
				}
				touchs.push(point)
				if (touchs.length >= 2) {
					this.draw(touchs)
				}
			},

			// 画布的触摸移动结束手势响应
			end: function(e) {
				//清空轨迹数组
				for (let i = 0; i < touchs.length; i++) {
					touchs.pop()
				}

			},

			// 画布的触摸取消响应
			cancel: function(e) {
				// console.log("触摸取消" + e)
			},

			// 画布的长按手势响应
			tap: function(e) {
				// console.log("长按手势" + e)
			},

			error: function(e) {
				// console.log("画布触摸错误" + e)
			},

			//绘制
			draw: function(touchs) {
				let point1 = touchs[0]
				let point2 = touchs[1]
				// console.log(JSON.stringify(touchs))
				content.moveTo(point1.x, point1.y)
				content.lineTo(point2.x, point2.y)
				content.stroke()
				content.draw(true);
				touchs.shift()

			},
			//清除操作
			clear: function() {
				//清除画布
				content.clearRect(0, 0, canvasw, canvash)
				content.draw(true)
				// this.close()
				this.hasDh = false;
				this.$emit('clear')
			},
			save(){
				var that = this;
				if(!this.hasDh){
					uni.showToast({title:'请先签字',icon:'none'})
					return;
				}
				uni.showLoading({title:'生成中...',mask:true})
				setTimeout(()=>{
					uni.canvasToTempFilePath({
						canvasId: this.canvasId,
						success: function(res) {
							that.signImage = res.tempFilePath;
							that.$emit('save',res.tempFilePath);
							uni.hideLoading()
							that.hasDh = false;
							that.show = false;
						},
						fail:function(err){
							console.log(err)
							uni.hideLoading()
						}
					},this)
				},100)
			}
		}
	}
</script>

<style lang="scss">
	.cat-signature.visible {
		visibility: visible
	}
	.cat-signature{
		display: block;
		position: fixed;
		top: 0;
		left: 0;
		right: 0;
		bottom: 0;
		overflow: hidden;
		z-index: 11;
		height: 100vh;
		visibility: hidden;
		.mask{display: block;opacity: 0;position: absolute;top: 0;left: 0;width: 100%;height: 100%;background: rgba(0, 0, 0, .4);transition: opacity .3s;}
		.content{display: block;position: absolute;top: 0;left: 0;bottom:0;right: 0;margin: auto; width:94%;height: 500upx;background: #fff;border-radius: 8upx;box-shadow: 0px 3px 3px #333;
			// canvas
			.firstCanvas {background-color: #fff;width: 100%;height: 400upx;}
			// canvas

			.btns{padding: 0 15px;height: 100upx;overflow: hidden; position: absolute;bottom: 10upx;left: 0;right: 0;margin: auto;display: flex;justify-content: space-between;
				.btn{width: 40%;text-align: center;font-size: 28upx;height:60upx;line-height: 60upx;background-color: #999;color: #fff;border-radius: 6upx;}
			}
		}
	}

	.visible .mask {
		display: block;
		opacity: 1
	}
</style>