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;}
