使用html5-qrcode 扫描二维码(vue3)

步骤：
1.安装库html5-qrcode : npm i html5-qrcode
2. 开启https(这里安装@vitejs/plugin-basic-ssl模拟)

// vite.config.js
import basicSsl from '@vitejs/plugin-basic-ssl'
export default defineConfig({
  plugins: [vue(),basicSsl()], // 这里写入插件 basicSsl
  resolve: {
    alias: {
      '@': fileURLToPath(new URL('./src',
        import.meta.url))
    }
  },
  server: { // ← ← ← ← ← ←
    port: 8082,
    proxy: {
      '/rss': {
        target: ENV_URL, //要访问的地址
        changeOrigin: true,
        rewrite: (path) => path.replace(/^\/rss/, ""),
        // secure: false
      }
    },
    https:true, // 这里开启https
    host: '0.0.0.0' // ← 新增内容 ←
  }
})

3.这里正式使用

// 新建scan.vue文件
<template>
  <div class="container">
    <div id="reader"></div>
  </div>
  <button @click="getCameras">扫码</button>
  <span>{{ result }}</span>
</template>

<script setup>
import { onMounted, ref, onUnmounted } from 'vue'
import { Html5Qrcode } from 'html5-qrcode'
import { showToast } from 'vant';

const cameraId = ref('')
const devicesInfo = ref('')
const html5QrCode = ref(null)
const result = ref('')
// const router = useRouter()

onMounted(() => {
  // getCameras()
})

onUnmounted(() => {
  stop()
})

const getCameras = () => {
  Html5Qrcode.getCameras()
    .then((devices) => {
      console.log('摄像头信息', devices)
      showToast('摄像头信息', devices)
      if (devices && devices.length) {
        // 如果有2个摄像头，1为前置的
        if (devices.length > 1) {
          cameraId.value = devices[1].id
        } else {
          cameraId.value = devices[0].id
        }
        devicesInfo.value = devices
        // start开始扫描
        start()
      }
    })
    .catch((err) => {
      // handle err
      console.log('获取设备信息失败', err) // 获取设备信息失败
      showToast('获取设备信息失败')
    })
}
const start = () => {
  html5QrCode.value = new Html5Qrcode('reader')
  console.log('html5QrCode', html5QrCode)

  html5QrCode.value.start(
    cameraId.value, // retreived in the previous step.
    {
      fps: 10, // 设置每秒多少帧
      qrbox: { width: 250, height: 250 } // 设置取景范围
      // scannable, rest shaded.
    },
    (decodedText, decodedResult) => {
      // do something when code is read. For example:
      // if (qrCodeMessage) {
      //   getCode(qrCodeMessage);
      //   stop();
      // }
      console.log('扫描的结果', decodedText, decodedResult)
      showToast('扫描的结果===', decodedText, decodedResult)
      result.value = decodedText
      if (decodedText) {
        stop();
      }
    },
    (errorMessage) => {
      // parse error, ideally ignore it. For example:
      // console.log(`QR Code no longer in front of camera.`);
      showToast('暂无扫描结果')
      console.log('暂无扫描结果', errorMessage)
      
    }
  )
    .catch((err) => {
      // Start failed, handle it. For example,
      console.log(`Unable to start scanning, error: ${err}`)
    })
}
const stop = () => {
  html5QrCode.value
    .stop()
    .then((ignore) => {
      // QR Code scanning is stopped.
      console.log('QR Code scanning stopped.', ignore)
      showToast('QR Code scanning stopped.')
    })
    .catch((err) => {
      // Stop failed, handle it.
      console.log('Unable to stop scanning.', err)
      showToast('Unable to stop scanning.')
    })
}
</script>

<style scoped>
.container {
  position: relative;
  height: 100%;
  width: 100%;
  background: rgba(#000000, 0.48);
}
#reader {
  top: 50%;
  left: 0;
  transform: translateY(-50%);
}
</style>

注意：要在https环境下才能使用