vue代码中上传二维码图片，并识别内容

识别二维码可以使用jsqr 或者 qrcode-decoder。我这采用的是jsqr。

1.安装

npm install jsqr

2.要使用的组件中引用

import jsQR from 'jsqr';

3.在Vue组件中创建处理QR码识别的方法

methods: {
  handleImageUpload(event) {
    const file = event.target.files[0];

    if (file) {
      const reader = new FileReader();

      reader.onload = (e) => {
        const imageData = new Image();
        imageData.onload = () => {
          const canvas = document.createElement('canvas');
          const context = canvas.getContext('2d');

          canvas.width = imageData.width;
          canvas.height = imageData.height;
          context.drawImage(imageData, 0, 0, imageData.width, imageData.height);

          const imageDataArray = context.getImageData(0, 0, imageData.width, imageData.height).data;
          const code = jsQR(imageDataArray, imageData.width, imageData.height);

          if (code) {
            const qrCodeData = code.data;
            console.log('QR Code Data:', qrCodeData);
            // You can now use qrCodeData as needed
          } else {
            console.error('QR Code not found');
          }
        };

        imageData.src = e.target.result;
      };

      reader.readAsDataURL(file);
    }
  },
},

4.在Vue模板中，创建一个用于文件上传的input元素，并将handlelmageUpload'方法附加到更改事件

<template>
  <div>
    <input type="file" @change="handleImageUpload" />
  </div>
</template>

创建一个类型为file的input元素，可以在其中上传包含二维码的图像。"handlelmageUpload'方法读取上传的图像，使用‘jsqr’对其进行处理，并提取二维码信息。
完整代码如下：

<template>
  <div>
    <input type="file" @change="handleImageUpload" />
  </div>
</template>

<script>
import jsQR from 'jsqr'
export default {
  props: {},
  data() {
    return {}
  },
  mounted() {},
  methods: {
    handleImageUpload(event) {
      const file = event.target.files[0]

      if (file) {
        const reader = new FileReader()

        reader.onload = (e) => {
          const imageData = new Image()
          imageData.onload = () => {
            const canvas = document.createElement('canvas')
            const context = canvas.getContext('2d')

            canvas.width = imageData.width
            canvas.height = imageData.height
            context.drawImage(
              imageData,
              0,
              0,
              imageData.width,
              imageData.height
            )

            const imageDataArray = context.getImageData(
              0,
              0,
              imageData.width,
              imageData.height
            ).data
            const code = jsQR(imageDataArray, imageData.width, imageData.height)

            if (code) {
              const qrCodeData = code.data
              console.log('QR Code Data:', qrCodeData)
              // You can now use qrCodeData as needed
            } else {
              console.error('QR Code not found')
            }
          }

          imageData.src = e.target.result
        }

        reader.readAsDataURL(file)
      }
    }
  }
}
</script>