Vue项目网页版在浏览器中实现扫码识别功能(项目应用篇）

需求：vue项目要求要在浏览器中调用摄像头进行扫一扫，并识别出二维码的字符串
插件：QRCodeReader
插件下载
npm install --save vue-qrcode-reader
注意： 需要在https协议下才可以调用相机，实现扫码。 可以通过配置vue.config.js中的devServer:{https:true}。说错了，是在：build/webpack.dev.conf.js里面

这步骤可省略：解决http下访问摄像头可见我下篇文章：https://www.cnblogs.com/Fancy1486450630/p/15719466.html
场景：点击扫一扫的图标，触发扫一扫功能，自动识别出数据之后，触发接口请求
公共组件页面（子页面）：scan.vue

<template>
	<div class="scan" v-if="scancode">
		<qrcode-stream @decode="onDecode" @init="onInit" style="height: 100vh;">
			<div>
				<div class="qr-scanner">
					<div class="box">
						<div class="line"></div>
						<div class="angle"></div>
					</div>
				</div>
			</div>
		</qrcode-stream>
	</div>
</template>
<script>
	// 下载插件
	// cnpm install --save  vue-qrcode-reader
	// 引入
	import {
		QrcodeStream
	} from 'vue-qrcode-reader'
	export default {
		// 注册
		components: {
			QrcodeStream
		},
		props: {
			scancode: {
				type: Boolean,
				default: false,
			}
		},
		data() {
			return {
				result: '', // 扫码结果信息
				error: '' // 错误信息
			}
		},
		created() {
			this.clickCode()
		},
		methods: {
			clickCode() {
				this.scancode = true;
			},
			//回调扫描结果
			onDecode(result) {

				if (result !== "") {
					this.scancode = false;
					this.$emit("ok", result)
				}

			},
			// 检查是否调用摄像头   
			async onInit(promise) {
				try {
					await promise
				} catch (error) {
					if (error.name === 'NotAllowedError') {
						this.error = "ERROR: 您需要授予相机访问权限"
					} else if (error.name === 'NotFoundError') {
						this.error = "ERROR: 这个设备上没有摄像头"
					} else if (error.name === 'NotSupportedError') {
						this.error = "ERROR: 所需的安全上下文(HTTPS、本地主机)"
					} else if (error.name === 'NotReadableError') {
						this.error = "ERROR: 相机被占用"
					} else if (error.name === 'OverconstrainedError') {
						this.error = "ERROR: 安装摄像头不合适"
					} else if (error.name === 'StreamApiNotSupportedError') {
						this.error = "ERROR: 此浏览器不支持流API"
					}
				}
			},
		}
	}
</script>
<style scoped>
	.error {
		font-weight: bold;
		color: red;
	}
</style>
<style scoped>
	.scan {
		 100vw;
		border-color: #585858;
		position: fixed;
		top: 0;
		left: 0;
	}

	.qrcode-stream-camera {
		 100%;
		height: 100%;
		display: block;
		-o-object-fit: cover;
		object-fit: cover;
		position: absolute;
		top: 0%;
		left: 0%;
	}

	.qr-scanner {
		background-image:
			linear-gradient(0deg,
				transparent 24%,
				rgba(32, 255, 77, 0.1) 25%,
				rgba(32, 255, 77, 0.1) 26%,
				transparent 27%,
				transparent 74%,
				rgba(32, 255, 77, 0.1) 75%,
				rgba(32, 255, 77, 0.1) 76%,
				transparent 77%,
				transparent),
			linear-gradient(90deg,
				transparent 24%,
				rgba(32, 255, 77, 0.1) 25%,
				rgba(32, 255, 77, 0.1) 26%,
				transparent 27%,
				transparent 74%,
				rgba(32, 255, 77, 0.1) 75%,
				rgba(32, 255, 77, 0.1) 76%,
				transparent 77%,
				transparent);
		background-size: 3rem 3rem;
		background-position: -1rem -1rem;
		 100%;
		/* height: 100%; */
		height: 100vh;
		position: relative;
		background-color: #1110;

		/* background-color: #111; */
	}

	.qr-scanner .box {
		 213px;
		height: 213px;
		position: absolute;
		left: 50%;
		top: 50%;
		transform: translate(-50%, -50%);
		overflow: hidden;
		border: 0.1rem solid rgba(0, 255, 51, 0.2);
		/* background: url('http://resource.beige.world/imgs/gongconghao.png') no-repeat center center; */
	}

	.qr-scanner .line {
		height: calc(100% - 2px);
		 100%;
		background: linear-gradient(180deg, rgba(0, 255, 51, 0) 43%, #00ff33 211%);
		border-bottom: 3px solid #00ff33;
		transform: translateY(-100%);
		animation: radar-beam 2s infinite alternate;
		animation-timing-function: cubic-bezier(0.53, 0, 0.43, 0.99);
		animation-delay: 1.4s;
	}

	.qr-scanner .box:after,
	.qr-scanner .box:before,
	.qr-scanner .angle:after,
	.qr-scanner .angle:before {
		content: '';
		display: block;
		position: absolute;
		 3vw;
		height: 3vw;

		border: 0.2rem solid transparent;
	}

	.qr-scanner .box:after,
	.qr-scanner .box:before {
		top: 0;
		border-top-color: #00ff33;
	}

	.qr-scanner .angle:after,
	.qr-scanner .angle:before {
		bottom: 0;
		border-bottom-color: #00ff33;
	}

	.qr-scanner .box:before,
	.qr-scanner .angle:before {
		left: 0;
		border-left-color: #00ff33;
	}

	.qr-scanner .box:after,
	.qr-scanner .angle:after {
		right: 0;
		border-right-color: #00ff33;
	}

	@keyframes radar-beam {
		0% {
			transform: translateY(-100%);
		}

		100% {
			transform: translateY(0);
		}
	}
</style>

父页面：

<div class="title">
	<span @click="clickCode">扫码</span>
	<scan :scancode='scancode' v-if="scancode" @ok="getResult" />
</div>
<script>
	import scan from './scan.vue'
	export default {
		components: {
			scan
		},
		data() {
			return {
				isShow: true, //页面其他文字内容隐藏
				scancode: false, //控制是否使用扫一扫功能
				result: '', //扫码结果信息
			}
		},
		methods: {
			// 打开相机
			clickCode() {
				this.isShow = false;
				this.scancode = true;
			},
			//返回扫描结果并关闭摄像头
			getResult(result) {
				console.log(this.result)
				this.result = result;
				if (result !== "") {
					this.$emit("result", result)
					this.isShow = true;
					this.deviceSN = result
					this.GetDeviceList(result) //拿到结果触发请求
					this.scancode = false;
				}
			},
		}
	}
</script>