来自DataURL的Blob？

用户Matt一年前提出了以下代码如何在javascript中将dataURL转换为文件对象？，这可能对您有帮助

编辑：正如一些评论者所报道的，BlobBuilder已被弃用了一段时间。这是更新的代码：

function dataURItoBlob(dataURI) {  // convert base64 to raw binary data held in a string  // doesn't handle URLEnpred DataURIs - see SO answer #6850276 for pre that does this  var byteString = atob(dataURI.split(',')[1]);  // separate out the mime component  var mimeString = dataURI.split(',')[0].split(':')[1].split(';')[0]  // write the bytes of the string to an ArrayBuffer  var ab = new ArrayBuffer(byteString.length);  // create a view into the buffer  var ia = new Uint8Array(ab);  // set the bytes of the buffer to the correct values  for (var i = 0; i < byteString.length; i++) {      ia[i] = byteString.charCodeAt(i);  }  // write the ArrayBuffer to a blob, and you're done  var blob = new Blob([ab], {type: mimeString});  return blob;}