nodejs如何把base64转换成blob

Question

nodejs如何把base64转换成blob

Answer 1

楼主，可以参考下
https://cklwblove.github.io/c...

/**
 * base64转blob
 *
 * @param {string} dataURL
 * @returns {*}
 * @example
 *
 * const URI = 'data:image/svg+xml;base64,PHN2ZyB2aWV3Qm94PSIwIDAgMTAyNCAxMDI0IiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSIyMDAiIGhlaWdodD0iMjAwIj48ZGVmcz48c3R5bGUvPjwvZGVmcz48cGF0aCBkPSJNOTU5LjQzNiAyNDMuNUwzNzcuNDEzIDg3MC4yNyA2NC4wMiA0NjcuMzQ0bDExNC43MjctOTcuOTMgMTk4LjY2NiAyMDcuMDYgNDkyLjQ4Mi00MjIuNTEgODkuNTQgODkuNTM3em0wIDAiIGZpbGw9IiM0M2E5ZjEiLz48L3N2Zz4=';
 *
 * dataURLToBlob(URI);
 * // => Blob {size: 248, type: "image/svg+xml"}
 */
function dataURLToBlob(dataURL) {
  var BASE64_MARKER = ';base64,';
  var parts;
  var contentType;
  var raw;
  if (dataURL.indexOf(BASE64_MARKER) === -1) {
    parts = dataURL.split(',');
    contentType = parts[0].split(':')[1];
    raw = decodeURIComponent(parts[1]);
    return new Blob([raw], {type: contentType});
  }
  parts = dataURL.split(BASE64_MARKER);
  contentType = parts[0].split(':')[1];
  raw = window.atob(parts[1]);
  var rawLength = raw.length;
  var uInt8Array = new Uint8Array(rawLength);
  for (var i = 0; i < rawLength; ++i) {
    uInt8Array[i] = raw.charCodeAt(i);
  }
  return new Blob([uInt8Array], {type: contentType});
}

Answer 2

function dataURLtoBlob (dataurl) {
  var arr = dataurl.split(','), mime = arr[0].match(/:(.*?);/)[1],
  bstr = atob(arr[1]), n = bstr.length, u8arr = new Uint8Array(n);
  while (n--) {
    u8arr[n] = bstr.charCodeAt(n);
  }
  return new Blob([u8arr], { type: mime });
}

var blob = dataURLtoBlob('data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7');
console.log(blob);