报警TimePicker问题ANDROID STUDIO

Question

我最近开始使用java编码，但我无法弄清楚TimePicker有什么问题。如果当前时间超过设定时间，则警报立即消失。如果设置时间超过当前时间，则报警正常工作。

AlarmManager alarmManager;
private PendingIntent pendingIntent;
private TimePicker alarmTimePicker;
private static AlarmActivity inst;
private TextView alarmTextView;

public static AlarmActivity instance() {
    return inst;
}

@Override
public void onStart() {
    super.onStart();
    inst = this;
}

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    alarmTimePicker = (TimePicker) findViewById(R.id.alarmTimePicker);
    alarmTextView = (TextView) findViewById(R.id.alarmText);
    ToggleButton alarmToggle = (ToggleButton) findViewById(R.id.alarmToggle);
    alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);
}

public void onToggleClicked(View view) {
    if (((ToggleButton) view).isChecked()) {
        Log.d("MyActivity", "Alarm On");
        Calendar calendar = Calendar.getInstance();
        calendar.set(Calendar.HOUR_OF_DAY, alarmTimePicker.getCurrentHour());
        calendar.set(Calendar.MINUTE, alarmTimePicker.getCurrentMinute());
        Intent myIntent = new Intent(AlarmActivity.this, AlarmReceiver.class);
        pendingIntent = PendingIntent.getBroadcast(AlarmActivity.this, 0, myIntent, 0);
        alarmManager.set(AlarmManager.RTC, calendar.getTimeInMillis(), pendingIntent);
    } else {
        alarmManager.cancel(pendingIntent);
        setAlarmText("");
        Log.d("MyActivity", "Alarm Off");
    }
}

public void setAlarmText(String alarmText) {
    alarmTextView.setText(alarmText);
}

这是我的闹钟接收器

public class AlarmReceiver extends WakefulBroadcastReceiver {

    @Override
    public void onReceive(final Context context, Intent intent) {

        AlarmActivity inst = AlarmActivity.instance();
        inst.setAlarmText("Alarm going.!");


        Uri alarmUri = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_ALARM);
        if (alarmUri == null) {
            alarmUri = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
        }
        Ringtone ringtone = RingtoneManager.getRingtone(context, alarmUri);
        ringtone.play();


        ComponentName comp = new ComponentName(context.getPackageName(),
                AlarmService.class.getName());
        startWakefulService(context, (intent.setComponent(comp)));
        setResultCode(Activity.RESULT_OK);
    }

谢谢。