在activity中运行两个android服务并从这两个服务中获取数据，然后在方法中使用哪一个？

我正在创建一个Android应用程序，在主活动上启动两个运行的服务，这两个服务将依次向每个活动传递一个字符串值。我已经创建了一个广播接收器来接收来自每个服务的数据。我的问题是，我想运行一个通知方法，在接收到两个字符串值之后，比较这两个字符串值。在启动这两个服务之后，我尝试过运行这个方法，但是我一直得到一个空指针异常。我想知道你是否可以使用一个广播接收器从不同的服务接收数据，因为如果可能的话，我可以在onReceive方法中运行这个方法。或者有什么方法可以解决这个空指针错误

以下是我的主要活动的onStart方法和通知方法：

String currentWeather;
String tweet;

...

@Override
protected void onStart()
{

  receiver = new BroadcastReceiver()
  {
     @Override
     public void onReceive(Context context, Intent intent)
     {

        currentWeather = intent.getStringExtra("weatherconditions");

     }
  };

  auroraReceiver = new BroadcastReceiver()
  {
     @Override
     public void onReceive(Context context, Intent intent)
     {
        tweet = intent.getStringExtra("latestTweet");
     }
  };

  IntentFilter intentFilter = new IntentFilter();
  intentFilter.addAction(WeatherService.BROADCAST);
  registerReceiver(receiver, intentFilter);

  IntentFilter auroraFilter = new IntentFilter();
  intentFilter.addAction(AuroraService.MY_ACTION);
  registerReceiver(auroraReceiver, auroraFilter);

  Intent newService = new Intent(getApplicationContext(), WeatherService.class);
  startService(newService);

  Intent auroraService = new Intent(getApplicationContext(), AuroraService.class);
  startService(auroraService);

  sendAuroraNotification();

  super.onStart();
}

public void sendAuroraNotification()
{

  if ((currentWeather.equals("Clear")) && (tweet.contains("red alert") || tweet.contains("amber alert")))
  {
     Intent thisIntent = new Intent(this, MyActivity.class);
     PendingIntent pIntent = PendingIntent.getActivity(this, 0, thisIntent, 0);
     NotificationCompat.Builder builder = new NotificationCompat.Builder(this)
             .setSmallIcon(R.drawable.notificationicon)
             .setContentTitle("Aurora Borealis")
             .setContentText("You can now view the Aurora Borealis in your area.")
             .setContentIntent(pIntent);

     notif.notify(001, builder.build());
  } else
  {
     myText.setText("No Notification yet");
  }

} 

在两个my Service类中发送数据的代码都很简单，并在onStartCommand方法中运行：

Intent sendInfo = new Intent();
sendInfo.setAction(BROADCAST);
sendInfo.putExtra("my_key", theString);
sendBroadcast(sendInfo);

编辑：

编辑2：

我已将代码更改为在OnReceive方法中从同一广播接收器接收两个字符串，然后在此之后调用sendAuroraNotification方法。但是，我仍然会遇到这样的错误：

07-25 17:11:36.413    5860-5860/com.example.Clear_Skies E/AndroidRuntime﹕ FATAL EXCEPTION: main
    Process: com.example.Clear_Skies, PID: 5860
    java.lang.RuntimeException: Error receiving broadcast Intent { act=receive_data flg=0x10 (has extras) } in com.example.Clear_Skies.MyActivity$1@423e5378
            at android.app.LoadedApk$ReceiverDispatcher$Args.run(LoadedApk.java:862)
            at android.os.Handler.handleCallback(Handler.java:733)
            at android.os.Handler.dispatchMessage(Handler.java:95)
            at android.os.Looper.loop(Looper.java:157)
            at android.app.ActivityThread.main(ActivityThread.java:5872)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:515)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:858)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:674)
            at dalvik.system.NativeStart.main(Native Method)
     Caused by: java.lang.NullPointerException
            at com.example.Clear_Skies.MyActivity.sendAuroraNotification(MyActivity.java:149)
            at com.example.Clear_Skies.MyActivity$1.onReceive(MyActivity.java:78)
            at android.app.LoadedApk$ReceiverDispatcher$Args.run(LoadedApk.java:848)
            at android.os.Handler.handleCallback(Handler.java:733)
            at android.os.Handler.dispatchMessage(Handler.java:95)
            at android.os.Looper.loop(Looper.java:157)
            at android.app.ActivityThread.main(ActivityThread.java:5872)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:515)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:858)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:674)
            at dalvik.system.NativeStart.main(Native Method)

以下是onStart方法的更新代码：

@Override

   protected void onStart()
   {

      receiver = new BroadcastReceiver()
      {
         @Override
         public void onReceive(Context context, Intent intent)
         {

            String currentWeather = intent.getStringExtra("weatherconditions");
            String tweet = intent.getStringExtra("latestTweet");
            sendAuroraNotification(currentWeather);

         }
      };

      IntentFilter intentFilter = new IntentFilter();
      intentFilter.addAction(RECEIVE_DATA);
      registerReceiver(receiver, intentFilter);

      Intent newService = new Intent(this, WeatherService.class);
      startService(newService);

      Intent auroraService = new Intent(this, AuroraService.class);
      startService(auroraService);

      super.onStart();
   }

IntentFilter intentFilter = new IntentFilter();
intentFilter.addAction(WeatherService.WEATHER_ACTION);
intentFilter.addAction(AuroraService.AURORA_ACTION);
registerReceiver(receiver, intentFilter);

logcat表示调用sendAuroraNotification方法时会发生空指针错误

编辑3：

我已通过以下更改成功解决了该问题：

启动方法：

@Override

   protected void onStart()
   {

      receiver = new BroadcastReceiver()
      {
         @Override
         public void onReceive(Context context, Intent intent)
         {

            String currentWeather = intent.getStringExtra("weatherconditions");
            String tweet = intent.getStringExtra("latestTweet");
            sendAuroraNotification(currentWeather);

         }
      };

      IntentFilter intentFilter = new IntentFilter();
      intentFilter.addAction(RECEIVE_DATA);
      registerReceiver(receiver, intentFilter);

      Intent newService = new Intent(this, WeatherService.class);
      startService(newService);

      Intent auroraService = new Intent(this, AuroraService.class);
      startService(auroraService);

      super.onStart();
   }

IntentFilter intentFilter = new IntentFilter();
intentFilter.addAction(WeatherService.WEATHER_ACTION);
intentFilter.addAction(AuroraService.AURORA_ACTION);
registerReceiver(receiver, intentFilter);

广播接收器的OnReceive方法：

 @Override
 public void onReceive(Context context, Intent intent)
 {
     String action = intent.getAction();
     String tweet="",currentWeather="";

    if (action.equalsIgnoreCase(AuroraService.AURORA_ACTION))
    {
       tweet = intent.getStringExtra("latestTweet");
    }

    if (action.equalsIgnoreCase(WeatherService.WEATHER_ACTION))
    {
       currentWeather = intent.getStringExtra("weatherconditions");
    }

       sendAuroraNotification(tweet,currentWeather);

 }

---

我的理解是，您希望检查从两个不同服务获得的两个字符串，并对它们进行比较。如果我没说错的话，你可以用同一个广播接收器来做这件事。使用相同的广播从您的服务接收值，一旦您获得这两个值，您就可以调用您的方法

sendAuroraNotification()

---

处理字符串。还要检查您是否正确初始化了notify object和textview对象。

myText.setTextNo Notification这是否在activity类或service类中？@IllegalArgument setText在activity类中，主要是为了测试MyActivity。java:166是notif.notify001，builder.build？可能是您忘了初始化notify objectI，为此我更改了代码。然而，我仍然收到一个错误，请参见上文，我测试了通过将值设置为TextView来查看是否接收到数据，这起到了作用，但一个字符串只有几行长，并且在几秒钟后一直消失。显示的意思是？？？发布您的更新代码，并指定您在哪一行获得错误。我现在发布了更新代码。消失意味着最初字符串在屏幕上出现了几秒钟，然后textView将没有任何文本。在调用sendAuroraNotification方法之前，您需要检查您是否具有这两个值