OkGo.<File>get(url)
                                .tag(this)
                                .execute(new FileCallbackDialog(mContext) {
                                    @Override
                                    public void onSuccess(Response<File> response) {
                                        File body = response.body();
                                        Intent intentBroadcast = new Intent(
                                                Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
                                        intentBroadcast.setData(Uri.fromFile(body));
                                        sendBroadcast(intentBroadcast);
                                        ToastUtils.showShort("已保存到相册<已下载>");
                                        sweetAlertDialog.dismiss();
                                    }
                                });

 Gif 下载 在手机已下载可以看到.