java - AlarmManager 在 Android 中不工作

Question

我正在学习 AlarmManager 的教程。我已经在模拟器中运行了教程的代码，但警报没有响起。 另外，教程在Calendar的第一个java类中使用了clone，为什么这里要clone呢？

任何帮助将不胜感激。

这是代码:

AndroidTimeActivity.java

public class AndroidTimeActivity extends Activity {

TimePicker myTimePicker;
Button buttonstartSetDialog;
TextView textAlarmPrompt;

TimePickerDialog timePickerDialog;

final static int RQS_1 = 1;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    textAlarmPrompt = (TextView)findViewById(R.id.alarmprompt);

    buttonstartSetDialog = (Button)findViewById(R.id.startSetDialog);
    buttonstartSetDialog.setOnClickListener(new OnClickListener(){

    @Override
    public void onClick(View v) {
    textAlarmPrompt.setText("");
    openTimePickerDialog(false);

        }
    });

}


private void openTimePickerDialog(boolean is24r){
    Calendar calendar = Calendar.getInstance();

    timePickerDialog = new TimePickerDialog(
    AndroidTimeActivity.this,
    onTimeSetListener,
    calendar.get(Calendar.HOUR_OF_DAY),
    calendar.get(Calendar.MINUTE),
    is24r);
    timePickerDialog.setTitle("Set Alarm Time");

    timePickerDialog.show();

}

OnTimeSetListener onTimeSetListener
    = new OnTimeSetListener(){

    @Override
    public void onTimeSet(TimePicker view, int hourOfDay, int minute) {

        Calendar calNow = Calendar.getInstance();
        Calendar calSet = (Calendar) calNow.clone();

        calSet.set(Calendar.HOUR_OF_DAY, hourOfDay);
        calSet.set(Calendar.MINUTE, minute);
        calSet.set(Calendar.SECOND, 0);
        calSet.set(Calendar.MILLISECOND, 0);

        if(calSet.compareTo(calNow) <= 0){
        //Today Set time passed, count to tomorrow
        calSet.add(Calendar.DATE, 1);
        }

        setAlarm(calSet);
    }
};

private void setAlarm(Calendar targetCal){

    textAlarmPrompt.setText(
    "\n\n***\n"
    + "Alarm is set@ " + targetCal.getTime() + "\n"
    + "***\n");

    Intent intent = new Intent(getBaseContext(), AlarmReceiver.class);
    PendingIntent pendingIntent = PendingIntent.getBroadcast(getBaseContext(), RQS_1, intent, 0);
    AlarmManager alarmManager = (AlarmManager)getSystemService(Context.ALARM_SERVICE);
    alarmManager.set(AlarmManager.RTC_WAKEUP, targetCal.getTimeInMillis(), pendingIntent);

}

}

AlarmReceiver.java

public class AlarmReceiver extends BroadcastReceiver {

@Override
public void onReceive(Context arg0, Intent arg1) {
Toast.makeText(arg0, "Alarm received!", Toast.LENGTH_LONG).show();
}
}

AndroidManifest.xml

<uses-permission android:name="com.android.alarm.permission.SET_ALARM" />


<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:supportsRtl="true"
    android:theme="@style/AppTheme" >
    <activity
        android:name=".AndroidTimeActivity"
        android:label="@string/app_name"
        android:theme="@style/AppTheme.NoActionBar" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>

    <Receiver
        android:name=".AlarmReciever"
        android:label="@string/title_activity_alarm_reciever"
        android:theme="@style/AppTheme.NoActionBar">
    </Receiver>
</application>

Answer 1

“Receiver”在 list 中拼写错误两次:

android:name=".AlarmReciever"
android:label="@string/title_activity_alarm_reciever"

应该是:

android:name=".AlarmReceiver"
android:label="@string/title_activity_alarm_receiver"