如何在颤振中使用回调在发送通知之前调用来安排和发送定期颤振本地通知

如何解决如何在颤振中使用回调在发送通知之前调用来安排和发送定期颤振本地通知

通过 Flutter 应用程序，我需要定期发送带有回调的本地通知——在发送通知之前，每个周期/间隔都会调用回调。 到目前为止，我已经尝试过 Timer 来安排定期的本地通知，但它在后台不起作用，即当应用程序关闭时。我也尝试过 FlutterlocalnotificationsPlugin.periodicallyShow，但是这个没有回调，它在发送通知之前被调用。最后，我尝试了 Firebase，但它需要在 Firebase 控制台中设置通知。如何在数据库更改后获取带有已完成和未决报告的回调通知。 请为上述问题提供解决方案。 这是我的代码：

import 'package:eclarity/pages/radiologist.dart';
import 'package:eclarity/pages/technici.dart';
import 'package:Flutter/material.dart';
import 'package:Flutter_local_notifications/Flutter_local_notifications.dart';
import 'package:http/http.dart' as http;
import 'dart:convert';
import 'package:shared_preferences/shared_preferences.dart';
import 'package:intl/intl.dart';
import 'package:android_alarm_manager/android_alarm_manager.dart';
import 'package:Flutter/cupertino.dart';
import 'dart:isolate';
import 'dart:math';
import 'dart:ui';
// import 'dart:ui';

import 'package:eclarity/pages/local_notifications.dart' as notify;

class HomePage extends StatefulWidget {
  @override
  _HomePageState createState() => _HomePageState();
}

class _HomePageState extends State {
  FlutterlocalnotificationsPlugin fltrNotification;
  String _selectedParam;
  String task;
  String task1;  
  int task2;
  String duration;
  String numCompleted;
  String numCompleted1;
  String numPending;
  String numPending1;
  String role;
  Timer timer;
  
  TextEditingController timeController;
  TextEditingController timeController1 = TextEditingController();

  int val;

  var url =  "http://";
   
 
  var data;
  // Future<Radiologist> _future;

  //Future<Radiologist> fetchReportStatus() async {
  fetchReportStatus() async {
    SharedPreferences prefs = await SharedPreferences.getInstance();
    int userPk = prefs?.getInt("userPk");

    String startDate2 = prefs?.getString("notifyDateTime");
    String startDate = prefs?.getString("loginDateTime");

    var currentTime =
        DateFormat('yyyy-MM-dd hh:mm:ss a').format(DateTime.Now());

    String role = prefs?.getString("role");
    bool userIsTechnician = true;
    if (role == "ROLE_RAdioLOGIST") {
      userIsTechnician = false;
    }

    //userIsTechnician
    Map data1 = {
      'authUserPk': userPk,"startDate": startDate,"endDate": currentTime,"userIsTechnician": userIsTechnician
    };

    String body1 = json.encode(data1);

    final response = await http.post(url,headers: <String,String>{
          'Content-Type': 'application/json; charset=UTF-8'
        },body: body1);

    if (response.statusCode == 200) {
      // If the server did return a 200 OK response,// then parse the JSON.
      if (userIsTechnician) {
        Technici r = Technici.fromJson(json.decode(response.body));
        this.numCompleted = r.numCompleted;
        this.numPending = r.numPending;
        print("tech===============" + response.body);
      } else {
        Radiologist r = Radiologist.fromJson(json.decode(response.body));
        this.numCompleted = r.numCompleted;
        this.numPending = r.numPending;
        print("rad===============" + response.body);

      }

      //return Radiologist.fromJson(json.decode(response.body));
    } else {
      // If the server did not return a 200 OK response,// then throw an exception.
      throw Exception('Failed to load report count');
    }
  }

/// The name associated with the UI isolate's [SendPort].
 String isolateName = 'isolate';

// /// A port used to communicate from a background isolate to the UI isolate.
final ReceivePort port = ReceivePort();
static SendPort uiSendPort;

  Future<void> showNotification(data) async {
    print(data);
    var rand = Random();
    var hash = rand.nextInt(100);
    DateTime Now = DateTime.Now().toUtc().add(Duration(seconds: 1));

    await notify.singleNotification(
      Now,"Hello $hash","This is hello message",hash,);
  }

  // The callback for our alarm
   Future<void> callback() async {
    print('Alarm fired!');
    // // This will be null if we're running in the background.
    uiSendPort ??= IsolateNameServer.lookupPortByName(isolateName);
    uiSendPort?.send("hi");

  }

  @override
  void initState() {
    super.initState();
    // _future =
    // fetchReportStatus();
   // repeatNotification();
//_showNotification();
  port.listen((data) async => await showNotification(data));

    runAlarm();
    WidgetsBinding.instance.addPostFrameCallback((_) async {
      timeController1.text = await getPrefForTimer3();
    });
   
    getPrefForTimer2().then((s) {
        task1 = s.toString();
    });
    
     getPrefForDuration().then((s) {
        _selectedParam = s;
    });

    var androidInitilize = new AndroidInitializationSettings('app_icon');
    var iOSinitilize = new IOSInitializationSettings();
    var initilizationsSettings = new InitializationSettings(
        android: androidInitilize,iOS: iOSinitilize);
    fltrNotification = new FlutterlocalnotificationsPlugin();
    fltrNotification.initialize(initilizationsSettings,onSelectNotification: notificationSelected);

      setDurationAndShowNotification();
     //  timerNotification(false);

  }

   void runAlarm() async {
    await AndroidAlarmManager.periodic(
      Duration(seconds: 1),callback,rescheduleOnReboot: true,exact: true,wakeup: true,);
    print("OK");
  }

   Future<String> getPrefForTimer3() async {
       SharedPreferences prefs = await SharedPreferences.getInstance();
         int taskInt = prefs.getInt("task") ?? 30;
         this.task1 = taskInt.toString();
        return this.task1;
   }
   Future<int> getPrefForTimer1() async {
       SharedPreferences prefs = await SharedPreferences.getInstance();
         int taskInt = prefs.getInt("task") ?? 30;
         this.task1 = taskInt.toString();
        return taskInt;
   }
  Future<int> getPrefForTimer2() async {
       SharedPreferences prefs = await SharedPreferences.getInstance();

         int taskInt = prefs.getInt("task") ?? 30;
         task1 = taskInt.toString();
                 return taskInt;

   }
  setPrefForTimer1(int val) async {
       SharedPreferences prefs = await SharedPreferences.getInstance();
      // setState(() {   
        prefs.setInt("task",val);
     //  });
   }

Future<String> getPrefForDuration() async {
       SharedPreferences prefs = await SharedPreferences.getInstance();
      setState(() {
        duration = prefs.getString("duration").toString() ?? "Minutes";
       });
        return duration;
   }
  setPrefForDuration(String val) async {
       SharedPreferences prefs = await SharedPreferences.getInstance();
        //setState(() {

        prefs.setString("duration",val);
       // });
   }
   

   getPrefForNumPending() async {
       SharedPreferences prefs = await SharedPreferences.getInstance();
        this.numPending1 = prefs.getInt("numPending").toString() ?? "-1";
   }
  setPrefForNumPending(String val) async {
       if (val == null) {return;}
       SharedPreferences prefs = await SharedPreferences.getInstance();
        prefs.setInt("numPending",int.parse(val));
   }

    getPrefForNumCompleted() async {
       SharedPreferences prefs = await SharedPreferences.getInstance();
        this.numCompleted1 = prefs.getInt("numCompleted").toString() ?? "0";
   }

    setPrefForNumCompleted(String val) async {
       if (val == null) {return;}
       SharedPreferences prefs = await SharedPreferences.getInstance();
        prefs.setInt("numCompleted",int.parse(val));
   }
   Future<bool> getUserIsTechnician() async {
    SharedPreferences prefs = await SharedPreferences.getInstance();

    String role = prefs?.getString("role");
    bool userIsTechnician = true;
    if (role == "ROLE_RAdioLOGIST") {
      userIsTechnician = false;
    }
    return userIsTechnician;
   }

  timerNotificationRestart() {
    if (this.task1 != null) {
      setPrefForTimer1(int.parse(this.task1));
    }
    //timerNotification(true);
  }

   timerNotification1(bool stop)  {
    if (stop && this.timer != null) {
      this.timer.cancel();
    }

    //getPrefForTimer1();
   if (this.task1 == null) {
     this.task2 = 30;
    } else {
      this.task2 = int.parse(task1);
    }
    
    Duration duration;
    if (_selectedParam == "Hour") {
      duration = Duration(hours: this.task2);
    } else {
      duration = Duration(minutes: this.task2);
    }
    
     
    bool isstopped = false;
    this.timer = Timer.periodic(duration,(timer1) async {
      // Make a local notification
      if (isstopped) {
        timer1.cancel();
      }


      var androidplatformChannelSpecifics = AndroidNotificationDetails(
          'your channel id','your channel name','your channel description',importance: Importance.max,priority: Priority.high,ticker: 'ticker');
      var iOSPlatformChannelSpecifics = IOSNotificationDetails();
      var platformChannelSpecifics = NotificationDetails(
          android: androidplatformChannelSpecifics,iOS: iOSPlatformChannelSpecifics);

     await fetchReportStatus();


    var value = await getUserIsTechnician();

     if (!value)  {

      getPrefForNumPending();

     bool sendNotification = false;
      if (this.numPending1 != null && this.numPending != null 
      && this.numPending != this.numPending1) {
        sendNotification = true;
      } else if (this.numPending1 == null) {
        sendNotification = true;
      }

      setPrefForNumPending(this.numPending);
      if (sendNotification) {
      await fltrNotification.show(
        
          0,"",// "# Report Completed :" +
        //     this.numCompleted +
        //     "\n","# Report Pending : " +
            this.numPending,platformChannelSpecifics,payload: 'item x');
      }
      }  else {
  getPrefForNumCompleted();
      bool sendNotification = false;
      if (this.numCompleted1 != null && this.numCompleted != null 
      && this.numCompleted != this.numCompleted1) {
        sendNotification = true;
      } else if (this.numCompleted1 == null) {
        sendNotification = true;
      }
      setPrefForNumCompleted(this.numCompleted);
      if (sendNotification) {
      await fltrNotification.show(
        
          0,"# Report Completed : " +
            this.numCompleted,payload: 'item x');

      }
      
      }

    });
  }
setDurationAndShowNotification() async {
   await fltrNotification.cancelAll();
  //await fltrNotification.cancel(1);
  
   showNotification1();
}


showNotification1() async {
// var schedulednotificationDateTime =
   //     new DateTime.Now().add(new Duration(seconds: 5));
  // Show a notification every minute with the first appearance happening a minute after invoking the method
var androidplatformChannelSpecifics =
    new AndroidNotificationDetails('repeating channel id 1','repeating channel name 1','repeating description 1');
var iOSPlatformChannelSpecifics =
    new IOSNotificationDetails();
var platformChannelSpecifics = new NotificationDetails(
    android: androidplatformChannelSpecifics,iOS: iOSPlatformChannelSpecifics);

    await fetchReportStatus();

    var value = await getUserIsTechnician();

   var interval;
    if (_selectedParam == "Hour") {
      interval = RepeatInterval.hourly;
    } else {
      interval = RepeatInterval.everyMinute;

    }
    
     if (!value)  {

     await getPrefForNumPending();
     bool sendNotification = false;
      if (this.numPending1 != null && this.numPending != null 
      && this.numPending != this.numPending1) {
        sendNotification = true;
      } else if (this.numPending1 == null) {
        sendNotification = true;
      }
        print("=========== About to send Rad Notification");
        print("num pending ===== " + this.numPending);
        print("num pending1 ===== " + this.numPending1);
        print("sendNotification ===== " + sendNotification.toString());

      setPrefForNumPending(this.numPending);
      if (sendNotification) {

        await fltrNotification.periodicallyShow(

        
          0,"eClarity Reprot Status","# Report Pending : " + this.numPending,interval,);
      }
      }  else {
  getPrefForNumCompleted();
      bool sendNotification = false;
      if (this.numCompleted1 != null && this.numCompleted != null 
      && this.numCompleted != this.numCompleted1) {
        sendNotification = true;
      } else if (this.numCompleted1 == null) {
        sendNotification = true;
      }

       print("=========== About to send Rad Notification");
        print("num completed ===== " + this.numCompleted.toString());
        print("num completed1 ===== " + this.numCompleted1.toString());
        print("sendNotification ===== " + sendNotification.toString());


      setPrefForNumCompleted(this.numCompleted);
      if (sendNotification) {
      await fltrNotification.periodicallyShow(
        
          0,);

      }
      
      }
}```