我在应用程序中使用flutter_downloader来允许下载PDF文件。它在Android中运行良好，但在IOS中，尽管在设备中下载了文件，但开始下载文件的通知不会出现。
我按照所有的说明一样，从启用后台模式，添加sqlite库，配置AppDelegate
验证码：

final status = await Permission.storage.request();
                                        if (status.isGranted) {

                                          // Directory _path  = await getExternalStorageDirectory();
                                          //  String _localPath = _path.absolute.path + Platform.pathSeparator + 'ESPRS_Docs';

                                          var savedDir;
                                          if (Platform.isIOS) {
                                            savedDir = await getApplicationDocumentsDirectory();
                                          } else {
                                            savedDir = Directory('/storage/emulated/0/Download');
                                            // Put file in global download folder, if for an unknown reason it didn't exist, we fallback
                                            // ignore: avoid_slow_async_io
                                            if (!await savedDir.exists()) savedDir = await getExternalStorageDirectory();
                                          }

                                          String random_no =randomAlphaNumeric(6) ;
                                          var split_name=p_title.replaceAll(" ","-");

                                           await FlutterDownloader.enqueue(
                                            url: p_link,
                                            savedDir: savedDir.path,
                                            fileName: "${split_name}-${random_no}.pdf",
                                            showNotification: true,
                                            saveInPublicStorage: true,
                                            openFileFromNotification: true,
                                            headers: {"auth": "Downloader"},

                                          );

                                        }else {
                                          print("Permission deined");
                                        };