最近H5项目用到了扫一扫，本来想用微信的结果只能在微信环境调，就在网上疯狂找插件，终于找到了，和大家分享一下

安装    cnpm install --save  vue-qrcode-reader

官方文档：vue-qrcode-reader 官方文档

一、创建组件

<template>
  <div class="scan">
    <qrcode-stream :camera="camera" @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 },
  data() {
    return {
	  camera: 'auto',
      result: '', // 扫码结果信息
      error: '' ,// 错误信息
	  scancode:true,
    }
  },
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) {
					// console.log()
					this.$toast(error.name)
                    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"
                    }else if (error.name === 'InsecureContextError') {
					  this.error =
						'ERROR: 仅允许在安全上下文中访问摄像机。使用HTTPS或本地主机，而不是HTTP。'
					} else {
					  this.error = 'ERROR:摄像机错误'
					}
			
					this.$emit("err",this.error)
                }
            },
  }
}
</script>
<style scoped>
.error {
  font-weight: bold;
  color: red;
}
</style>
<style scoped>
  @import '../css/scancode.scss';
</style>

二、导入css

.scan{
    width: 100vw;
    border-color: #585858;
    position: fixed;
    top: 0;
    left: 0;
}
.qrcode-stream-camera{
    width: 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;
      width: 100%;
      /* height: 100%; */
      height: 100vh;
      position: relative;
      /* background-color: #1110;*/
  
      /* background-color: #111; */
    }
  
    .qr-scanner .box {
      width: 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);
      width: 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;
      width: 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);
      }
    }

3、扫一扫页面

<template>
	<div class="sys">
		<van-nav-bar @click-left="onClickLeft" :safe-area-inset-top="true" title="扫一扫" left-arrow :placeholder="true"
			:fixed="true"></van-nav-bar>
		<BarScan @ok="getResult" @err="geterror" ></BarScan>
	</div>
</template>

<script>
	import BarScan from '../../components/scan.vue'
	export default {
		components:{
			BarScan
		},
		data() {
			return {
				result:''
			}
		},
		created() {
		},
		methods:{
			onClickLeft(){
				this.$router.go(-1);
			},
			getResult(result){
			      this.result=result;
			},
			geterror(e){
				this.scancode=false;
				this.$toast(e)
			},
		}
	}
</script>

<style>
	.sys{
		width: 100vw;
		height: 100vh;
		background: #111;
	}
</style>

注意事项：

进入扫一扫页面前一个页面缓存会消失，需要使用keep-alive

keep-alive 缓存不更新问题

认为这个扫码识别比较慢也可以看我主页的另一个扫码功能  

VUE html5-qrcode H5扫一扫功能