下载二维码

downloQRcode() {//下载二维码
  let div = document.getElementsByClassName('qrcode')
  downloadFile(this.qrcodeName, div[0].getElementsByTagName('img')[0].src)
},

function downloadFile(fileName, content) {//下载
  let aLink = document.createElement('a');
  let blob = base64ToBlob(content); //new Blob([content]);
  let evt = document.createEvent("HTMLEvents");
  evt.initEvent("click", true, true);
  aLink.download = fileName;
  aLink.href = URL.createObjectURL(blob);
  aLink.click()
}

function base64ToBlob(code) {//base64转blob二进制流
  let parts = code.split(';base64,');
  let contentType = parts[0].split(':')[1];
  let raw = window.atob(parts[1]);
  let rawLength = raw.length;
  let uInt8Array = new Uint8Array(rawLength);
  for (let i = 0; i < rawLength; ++i) {
    uInt8Array[i] = raw.charCodeAt(i);
  }
  return new Blob([uInt8Array], {type: contentType});
}