设置闹钟后无法显示警报消息

Question

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
    public void scheduleAlarm(View V){
        //Long time= new GregorianCalendar().getTimeInMillis()+24*60*60*1000;
        Long time= new GregorianCalendar().getTimeInMillis()+30*1000;
            Intent intentAlarm= new Intent(this, AlarmReceiver.class);
        AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
        alarmManager.set(AlarmManager.RTC_WAKEUP, time, PendingIntent.getBroadcast(this, 1, intentAlarm, PendingIntent.FLAG_UPDATE_CURRENT));
        Toast.makeText(this, "Alarm Scheduled for 30 repetd", Toast.LENGTH_LONG).show();
    }


}

AlarmReceiverClass

   public class AlarmReceiver extends BroadcastReceiver{

        @Override
        public void onReceive(Context context, Intent intent) {
            // TODO Auto-generated method stub

            Toast.makeText(context, "Alarm Triggered and SMS Sent", Toast.LENGTH_LONG);
        }

    }

这是我的代码，我正在尝试设置警报并每 30 秒显示一次警报消息但是我无法在 toast 中显示警报混乱，而我编写的代码都是正确的，但我不知道我在做什么错误请看我的代码，请告诉我哪里做错了。

Answer 1

首先请在toast中加入.show()。即 Toast.makeText(context, "Alarm Triggered and SMS Sent", Toast.LENGTH_LONG).show();

编辑

请使用以下代码：

清单中

 <receiver android:name=".alarm.manager.Alarm" >
        </receiver>

创建一个名为 AlarmService.java

的新 class

public class AlarmService extends Service {
    Alarm alarm = new Alarm();

    public void onCreate() {
        super.onCreate();
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        alarm.SetAlarm(AlarmService.this);
        return START_STICKY;
    }

    public void onStart(Context context, Intent intent, int startId) {
        alarm.SetAlarm(context);
    }

    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }
}

另一个classalarm.java

package alarm.manager;


import android.annotation.SuppressLint;
import android.annotation.TargetApi;
import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.os.Build;
import android.os.PowerManager;
import android.util.Log;





public class Alarm extends BroadcastReceiver  {


    public static final String ALARM_SERVICE = "alarm";

    public Alarm() {

    }




    Context mContext;

    @TargetApi(Build.VERSION_CODES.JELLY_BEAN)
    @SuppressLint("NewApi")
    @Override
    public void onReceive(Context context, Intent intent) {

        PowerManager pm = (PowerManager) context
                .getSystemService(Context.POWER_SERVICE);
        PowerManager.WakeLock wl = pm.newWakeLock(
                PowerManager.PARTIAL_WAKE_LOCK, "");
        wl.acquire();
        mContext = context;


        Log.d("App", "Alarm manager invoked");



        wl.release();
    }


    public void SetAlarm(Context context) {
        AlarmManager am = (AlarmManager) context
                .getSystemService(Context.ALARM_SERVICE);

        Intent i = new Intent(context, Alarm.class);
        PendingIntent pi = PendingIntent.getBroadcast(context, 0, i, 0);
        am.setRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis(),
                1000, pi); 

    }

    /**
     * Stop alarm
     * 
     * @param context
     *            = context of activity
     */
    public void CancelAlarm(Context context) {
        Intent intent = new Intent(context, Alarm.class);
        PendingIntent sender = PendingIntent
                .getBroadcast(context, 0, intent, 0);
        AlarmManager alarmManager = (AlarmManager) context
                .getSystemService(Context.ALARM_SERVICE);
        alarmManager.cancel(sender);
    }



}

从您的 class 调用这些行

Alarm alarm = new Alarm();
alarm.SetAlarm(getApplicationContext());

Answer 2

您刚刚错过了为 Toast 调用 .show() 方法。所以会是

Toast.makeText(context, "Alarm Triggered and SMS Sent", Toast.LENGTH_LONG).show();

设置闹钟后无法显示警报消息

Unable to display Alarm messge when alarm is set

android

broadcastreceiver

alarmmanager