遇到一个关于上传多张base64图片的问题，想先将base64图片转成blob对象

Question

第一步转为blob对象没问题：function dataURItoBlob (base64Data) {var byteString;if (base64Data.split(',')[0].indexOf('base64') >= 0){  byteString = atob(base64Data.split(',')[1]);}else{  byteString = unescape(base64Data.split(',')[1]);}var mimeString = base64Data.split(',')[0].split(':')[1].split(';')[0];var ia = new Uint8Array(byteString.length);for (var i = 0; i < byteString.length; i++) {    ia[i] = byteString.charCodeAt(i);}return new Blob([ia], {type:mimeString});}但是第二步将blob对象放入到formdata中感觉不对：var fd = new FormData(obj);var blob = dataURItoBlob (base64,'mimeString');fd.append("files[]", blob);当我用ajax上传给后台的时候，报错405