如何从原生发送数据到Flutter（Android）

Question

我需要将数据从下面的类传递到我的 flutter 应用程序，其中数据仅在发生来电事件时可用。我需要将此数据（mobileNumber）传递给flutter（如果可能的话，即使flutter应用程序终止，我也需要传递数据）

广播接收器.java

package com.ashbu.flutterappbackground;
...

public class MyBroadcastReceiver extends BroadcastReceiver {
    String phoneNumber;

        @Override
        public void onReceive(final Context context, Intent intent) {
            TelephonyManager telephony = (TelephonyManager)context.getSystemService(Service.TELEPHONY_SERVICE);
            telephony.listen(new PhoneStateListener(){
                @Override
                public void onCallStateChanged(int state, String incomingNumber) {
                    super.onCallStateChanged(state, incomingNumber);
                    phoneNumber = incomingNumber;
                    Toast.makeText(context, "TeleDuce Customer "+ incomingNumber,
                Toast.LENGTH_LONG).show();
                }
            },PhoneStateListener.LISTEN_CALL_STATE);
        }


   public  String getData() {
    String number = null;
    if (phoneNumber != null) {
        number = phoneNumber;
    }else {
        number = "noData";
    }
    return number;
    }

从上面的代码中，我需要将传入编号传递给flutter。如果可能 - 即使应用程序关闭也共享数据。

MainActivity.java

public class MainActivity extends FlutterActivity {
private static final String CHANNEL = "samples.flutter.dev/getNumber";

AlarmManager alarmManager;
PendingIntent pendingIntent;

@Override
public void configureFlutterEngine(@NonNull FlutterEngine flutterEngine) {
    super.configureFlutterEngine(flutterEngine);
    alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
    Intent alarmIntent = new Intent(this, MyService.class);
    pendingIntent = PendingIntent.getBroadcast(this, 0, alarmIntent, 0);

    new MethodChannel(flutterEngine.getDartExecutor().getBinaryMessenger(), CHANNEL)
            .setMethodCallHandler(
                    (call, result) -> {

                        // Note: this method is invoked on the main thread.
                        if (call.method.equals("getMobileNumber")) {
                            startAlarm();
                            MyBroadcastReceiver dataGEt = new MyBroadcastReceiver();
                            System.out.println(dataGEt.getData());
                            result.success(dataGEt.getData());
                        } else {
                            cancelAlarm();
                        }
                    }
            );
}

private void startAlarm() {

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
        alarmManager.setAndAllowWhileIdle(AlarmManager.RTC_WAKEUP, 0, pendingIntent);
    } else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
        alarmManager.setExact(AlarmManager.RTC_WAKEUP, 0, pendingIntent);
    } else {
        alarmManager.set(AlarmManager.RTC_WAKEUP, 0, pendingIntent);
    }
}

private void cancelAlarm() {
    alarmManager.cancel(pendingIntent);
    Toast.makeText(getApplicationContext(), "Alarm Cancelled", Toast.LENGTH_LONG).show();
}
}

目前，即使应用程序终止，上述代码也将起作用。但我不知道应用程序终止后flutter是否会接受数据

Answer 1

您应该在 Flutterside 中实现methodHandler，并且应该使 methodchannel 成为静态对象

例如

class MethodChannelHelper {
  static const MethodChannel channel = const MethodChannel('method_channal_name');
}
class MethodChannelCall{
        static initMethodChannel({Function onCallBack}) async {
            MethodChannelHelper.channel.setMethodCallHandler((MethodCall call) async {
              switch (call.method) {
                case 'callback_from_native':
                  print("This method will be called when native fire")
              }
            });
     await MethodChannelHelper.channel.invokeMethod('call_native');
          }
}

在main.dart中

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await MethodChannelCall.initMethodChannel(onCallBack: (payload) {

  });
  runApp(MyApp());
}

现在在Android端

 override fun onMethodCall(@NonNull call: MethodCall, @NonNull result: Result) {
 when (call.method) {
            "call_native" -> {
            methodChannel?.invokeMethod("callback_from_native","")

}
}