我有一個(gè) Android 應(yīng)用程序，需要讓用戶從圖庫中選擇一些圖片并將這些圖片發(fā)送到后端（連同一些其他數(shù)據(jù)）。為了讓用戶選擇我的片段中的圖片：private void pickImages() {    Intent intent = new Intent(Intent.ACTION_GET_CONTENT);    intent.setType("image/*");    intent.putExtra(Intent.EXTRA_ALLOW_MULTIPLE, true);    startActivityForResult(intent, PICK_PHOTO_FOR_AVATAR);}我在這里得到用戶選擇的照片的結(jié)果：@Overridepublic void onActivityResult(int requestCode, int resultCode, Intent data) {    super.onActivityResult(requestCode, resultCode, data);    if (requestCode == PICK_PHOTO_FOR_AVATAR && resultCode == Activity.RESULT_OK) {        if (data == null) {            //Display an error            Toast.makeText(getActivity(), "There was an error getting the pictures", Toast.LENGTH_LONG).show();           return;        }        ClipData clipData = data.getClipData();        String fileName = null, extension = null;        //if ClipData is null, then we have a regular file        if (clipData == null) {            //get the selected file uri            fileName = FileUtils.getPath(getActivity(), data.getData());            //obtain the extension of the file            int index = fileName.lastIndexOf('.');            if (index > 0) {                extension = fileName.substring(index + 1);                if (extension.equals("jpg") || extension.equals("png") || extension.equals("bmp") || extension.equals("jpeg"))                    isAttachedFile = true;            }        }        ArrayList<Uri> photosUris = new ArrayList<>();        //for each image in the list of images, add it to the filesUris        if (clipData != null) for (int i = 0; i < clipData.getItemCount(); i++) {            ClipData.Item item = clipData.getItemAt(i);            Uri uri = item.getUri();            switch (i) {                case 0:                    picture1Uri = uri;                    break;                case 1:                    picture2Uri = uri;                    break;            }