試圖從活動崩潰中將值傳遞給廣播接收器應用

我想根據this問題將值從活動傳遞給廣播接收器。試圖從活動崩潰中將值傳遞給廣播接收器應用

但是，這樣做會導致我的應用程序崩潰。這是我的活動代碼。

private void setAlarm(Calendar targetCal) 
{ 

    Intent in = new Intent("my.action.string"); 
    in.putExtra("ALARM_NO", tempx); 
    sendBroadcast(in); 

    Intent alarmintent = new Intent(AddAlarm.this, AlarmReceiver.class); 
    PendingIntent sender = PendingIntent.getBroadcast(AddAlarm.this, pen, alarmintent, PendingIntent.FLAG_ONE_SHOT); 
    AlarmManager alarmManager = (AlarmManager)getSystemService(ALARM_SERVICE); 
    alarmManager.setExact(AlarmManager.RTC_WAKEUP, targetCal.getTimeInMillis(), sender); 


}

這裏是廣播接收器的代碼，以及：

public void onReceive(final Context context, Intent intent) { 
    int state; 
    String action = intent.getAction(); 

    Log.i("Receiver", "Broadcast received: " + action); 

    if(action.equals("my.action.string")) 
    { 
     state = intent.getIntExtra("ALARM_NO",0); 

    } 

    if(state==1) { 

     //intent to call the activity which shows on ringing 
     Intent myIntent = new Intent(context, Time_Date.class); 
     myIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK); 
     context.startActivity(myIntent); 
    } 

    if(state==2) 
    { 
     //intent to call the activity which shows on ringing 
     Intent myIntent = new Intent(context, AlarmLaunch2.class); 
     myIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK); 
     context.startActivity(myIntent); 
    }

而這正是我在logcat中獲得。

> 07-21 16:40:40.769 26721-26721/zyia.alarm.zyia.zyia E/AndroidRuntime﹕ FATAL EXCEPTION: main 
    Process: zyia.alarm.zyia.zyia, PID: 26721 
    java.lang.RuntimeException: Unable to start receiver zyia.alarm.zyia.zyia.AlarmReceiver: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean java.lang.String.equals(java.lang.Object)' on a null object reference 
      at android.app.ActivityThread.handleReceiver(ActivityThread.java:2616) 
      at android.app.ActivityThread.access$1700(ActivityThread.java:151) 
      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1380) 
      at android.os.Handler.dispatchMessage(Handler.java:102) 
      at android.os.Looper.loop(Looper.java:135) 
      at android.app.ActivityThread.main(ActivityThread.java:5254) 
      at java.lang.reflect.Method.invoke(Native Method) 
      at java.lang.reflect.Method.invoke(Method.java:372) 
      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903) 
      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698) 
    Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean java.lang.String.equals(java.lang.Object)' on a null object reference 
      at zyia.alarm.zyia.zyia.AlarmReceiver.onReceive(AlarmReceiver.java:29) 
      at android.app.ActivityThread.handleReceiver(ActivityThread.java:2609) 
            at android.app.ActivityThread.access$1700(ActivityThread.java:151) 
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1380) 
            at android.os.Handler.dispatchMessage(Handler.java:102) 
            at android.os.Looper.loop(Looper.java:135) 
            at android.app.ActivityThread.main(ActivityThread.java:5254) 
            at java.lang.reflect.Method.invoke(Native Method) 
            at java.lang.reflect.Method.invoke(Method.java:372) 
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903) 
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)

那麼，什麼導致空指針異常？以及如何解決這個問題？任何幫助將不勝感激。

來源

2015-07-21 OBX

你應該立足於回答，不是問題;） – GVillani82

是的，我用的代碼來自Answer – OBX

什麼是寫在29行 –

你應該做的，如：

private void setAlarm(Calendar targetCal) 
{ 
    Intent alarmintent = new Intent(AddAlarm.this, AlarmReceiver.class); 
    alarmintent.putExtra("ALARM_NO", tempx); 
    alarmintent.setAction("my.action.string"); 
    PendingIntent sender = PendingIntent.getBroadcast(AddAlarm.this, pen, alarmintent, PendingIntent.FLAG_ONE_SHOT); 

    AlarmManager alarmManager = (AlarmManager)getSystemService(ALARM_SERVICE); 
    alarmManager.setExact(AlarmManager.RTC_WAKEUP, targetCal.getTimeInMillis(), sender); 


}

alarmintent.setAction（「my.action.string」）;

來源

2015-07-21 11:27:44

完美答案。有用。 +1的幫助:) – OBX

您可以通過撒施接收器使用putExtra本身

private void setAlarm(Calendar targetCal) 
    { 
     Intent alarmintent = new Intent(AddAlarm.this, AlarmReceiver.class); 
    alarmintent .putExtra("action", "my.action.string"); 
     PendingIntent sender = PendingIntent.getBroadcast(AddAlarm.this, pen, alarmintent, PendingIntent.FLAG_ONE_SHOT); 
     AlarmManager alarmManager = (AlarmManager)getSystemService(ALARM_SERVICE); 
     alarmManager.setExact(AlarmManager.RTC_WAKEUP, targetCal.getTimeInMillis(), sender); 

    }

getStringExtra（「行動」）比較

來源

2015-07-21 11:28:07

試圖從活動崩潰中將值傳遞給廣播接收器應用

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