xc-qrcode/index.js

decode qrcode

import gzip from 'lrz';
import qrcodeParser from 'qrcode-parser';
// 将图片转成base64位的png
function image2PngBase64(img) {
  var canvas = document.createElement("canvas");
  canvas.width = img.width;
  canvas.height = img.height;
  var ctx = canvas.getContext("2d");
  ctx.drawImage(img, 0, 0, img.width, img.height);
  var dataURL = canvas.toDataURL("image/png");
  return dataURL;
}
// 加载图片并转为png格式的base64
function loadImage(img) {
  return new Promise((resolve, reject) => {
    img.onload = () => {
      const base64 = image2PngBase64(img);
      resolve(base64);
    };
    img.onerror = () => {
      reject();
    };
  });
}
// 解析二维码
async function parseQrcode(file) {
  let msg = "";
  const gzipImg = await gzip(URL.createObjectURL(file.raw));
  let img = new Image();
  img.src = gzipImg.base64;
  const pngBase64 = await loadImage(img);
  try {
    msg = await qrcodeParser(pngBase64);
      return msg;
  } catch (err) {
    return 'decode error';
  }
}

export default  parseQrcode