【问题标题】:Android - AlarmManager fires every 5 seconds instead of 3 minutesAndroid - AlarmManager 每 5 秒而不是 3 分钟触发一次
【发布时间】:2020-01-02 11:08:54
【问题描述】:

我搜索了很多地方,但找不到解决方案。我是 Android/Java 编程的新手,我正在尝试制作一个应用程序,每天(exact time)从 SharedPreferences 将计数器保存在 SQLite 数据库中并将其重置为 0(如计步器) .

我正在使用 AlarmManager 和 BroadcastReceiver。
我第一次在其中一个活动中使用 "setExactAndAllowWhileIdle" 设置警报,然后是 BroadcastReceiver 的 onReceive() 我正在调用 restartAlarm() 方法来重新安排警报。

问题
警报在特定时间首次正确触发(例如 14:00:00)。
也在 3 分钟 (14:03:00) 后重新安排并正确触发,但只有一次。

我面临的问题是,在 3 分钟后第一次重新安排警报触发后(来自 BroadcastReceiver 中的 restartAlarm() 方法),然后警报每 5 秒而不是 3 分钟触发一次( 我想要每天重复闹钟,但我每 3 分钟设置一次闹钟仅用于测试结果)。

这就是我正在做的事情:

我在 Manifest.xml 文件中设置权限和接收者

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />

<application
    android:name=".ApplicationClass"
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:roundIcon="@mipmap/ic_launcher_round"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">

    ....

    <receiver
        android:name=".MyAlarmReceiver"
        android:directBootAware="true"
        android:enabled="true"
        android:exported="true">
        <intent-filter>
            <action android:name="android.intent.action.BOOT_COMPLETED" />
            <action android:name="android.intent.action.LOCKED_BOOT_COMPLETED" />
        </intent-filter>
    </receiver>

</application>

在应用程序的一项活动中启动警报:

public class CompleteRegistered extends AppCompatActivity {

...

public static AlarmManager alarmManager;
public static PendingIntent pendingIntent;
private static final int GLASS_REQUEST_CODE = 101;

...


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_complete_registered);

    ...

    startAlarmManager();
}

private void startAlarmManager(){

    // Creating the pending intent to send to the BroadcastReceiver
    alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
    Intent alarmIntent = new Intent(getApplicationContext(), MyAlarmReceiver.class);
    pendingIntent = PendingIntent.getBroadcast(this, GLASS_REQUEST_CODE, alarmIntent, PendingIntent.FLAG_UPDATE_CURRENT);

    // Setting the specific time for the alarm manager to trigger the intent
    Calendar startTime = Calendar.getInstance();
    startTime.setTimeInMillis(System.currentTimeMillis());
    startTime.set(Calendar.HOUR_OF_DAY, 14);
    startTime.set(Calendar.MINUTE, 0);
    startTime.set(Calendar.SECOND, 0);


    // Starts the alarm manager
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {

        alarmManager.setExactAndAllowWhileIdle(AlarmManager.RTC, startTime.getTimeInMillis(), pendingIntent);

    } else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {

        alarmManager.setExact(AlarmManager.RTC, startTime.getTimeInMillis(), pendingIntent);

    } else {

        alarmManager.set(AlarmManager.RTC, startTime.getTimeInMillis(), pendingIntent);
    }

}

将计数器保存到 SQLite 数据库并在 BroadcastReceiver 中重新安排警报:

public class MyAlarmReceiver extends BroadcastReceiver {

private static final String MyPREFERENCES = "MyPrefs" ;
private SharedPreferences sharedpreferences;

public static AlarmManager alarmManager;
public static PendingIntent pendingIntent;
public static Intent alarmIntent;
private static final int GLASS_REQUEST_CODE = 102;

// Database Helper
private DatabaseHelper db;

public void restartAlarm(Context context){

    // Creating the pending intent to send to the BroadcastReceiver
    alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
    alarmIntent = new Intent(context, MyAlarmReceiver.class);
    pendingIntent = PendingIntent.getBroadcast(context, GLASS_REQUEST_CODE, alarmIntent, PendingIntent.FLAG_UPDATE_CURRENT);

    // Setting the specific time for the alarm manager to trigger the intent
    Calendar startTime = Calendar.getInstance();
    startTime.setTimeInMillis(System.currentTimeMillis());
    startTime.set(Calendar.HOUR_OF_DAY, 14);
    startTime.set(Calendar.MINUTE, 0);
    startTime.set(Calendar.SECOND, 0);

    // Getting time
    Calendar now = Calendar.getInstance();

    if (now.after(startTime)){

        // startTime.add(Calendar.DATE, 1);
        startTime.add(Calendar.MINUTE, 3);
    }


    // Starts the alarm manager
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {

        alarmManager.setExactAndAllowWhileIdle(AlarmManager.RTC, startTime.getTimeInMillis(), pendingIntent);

    } else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {

        alarmManager.setExact(AlarmManager.RTC, startTime.getTimeInMillis(), pendingIntent);

    } else {

        alarmManager.set(AlarmManager.RTC, startTime.getTimeInMillis(), pendingIntent);
    }

}


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

    // When device reboots
    if (intent.getAction() == Intent.ACTION_BOOT_COMPLETED) {

        // Set the alarm.
        startAlarm(context);

    }
    else {
        sharedpreferences = context.getSharedPreferences(MyPREFERENCES, Activity.MODE_PRIVATE);
        final SharedPreferences.Editor editor = sharedpreferences.edit();

        // Get glasses from SharedPreferences
        int glassCounter = sharedpreferences.getInt("glasses", 0);

        // Create a WaterTracker
        WaterTracker waterTracker = new WaterTracker();
        waterTracker.setGlasses(glassCounter);

        // Store to SQLite database
        db = new DatabaseHelper(context);
        db.createWaterTracker(waterTracker);

        // Reset glasses from SharedPreferences
        editor.putInt("glasses", 0);
        editor.apply();

        // Set the alarm again.
        restartAlarm(context);
    }
}

我还有一个扩展应用程序的应用程序类:

public class ApplicationClass extends Application {

    ...

    public static AlarmManager alarmManager;
    public static PendingIntent pendingIntent;
    private static final int GLASS_REQUEST_CODE = 101;

    @RequiresApi(api = Build.VERSION_CODES.M)
    @Override
    public void onCreate() {
        super.onCreate();

        ...

        ComponentName receiver = new ComponentName(getApplicationContext(), MyAlarmReceiver.class);
        PackageManager pm = getApplicationContext().getPackageManager();

        pm.setComponentEnabledSetting(receiver,
                PackageManager.COMPONENT_ENABLED_STATE_ENABLED,
                PackageManager.DONT_KILL_APP);

    }
}

我从这段代码中得到的结果是:
1.(计数器值)在 14:00:00
2.(计数器值)在 14:03:00
3.(计数器值)在 14:03:05
4.(计数器值)在 14:03:10
5.(计数器值)在 14:03:15
6.(计数器值)在 14:03:20
7.(计数器值)在 14:03:25
8.(计数器值)14:03:30
...
?. (计数器值)在 14:05:25

对此的任何帮助将不胜感激!
提前谢谢!

【问题讨论】:

  • 你想每 5 分钟重复一次警报,你可以使用 setInexactRepeating() 方法,因为上面的代码对于给定的任务相当复杂。
  • 问题是当您在内部测试时,如果 (now.after(startTime)) 一天中的小时总是超过 14 并且警报会尽快触发。您应该将 startTime 重置为 now + 3 分钟

标签: java android broadcastreceiver alarmmanager repeatingalarm


【解决方案1】:

试试这个重复警报管理器的任务。

private void repeateAlarm() {

    Calendar updateTime = Calendar.getInstance();

    updateTime.set(alendar.MINUTE, 3);

    Intent alarmIntent = new Intent(this, AlarmReceiver.class);
    PendingIntent recurringDownload = PendingIntent.getBroadcast(this, 0, alarmIntent, PendingIntent.FLAG_CANCEL_CURRENT);
    AlarmManager alarms = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
    alarms.cancel(recurringDownload);
    alarms.setInexactRepeating(AlarmManager.RTC_WAKEUP, updateTime.getTimeInMillis(), 1000 * 60*3, recurringDownload); // it will run in every 3 min
}

【讨论】:

  • 我正在使用 setExactAndAllowWhileIdle 因为我想在特定时间重复警报。我认为 setInexactRepeating 没有这样做。虽然我会试一试。
  • 我仍然遇到同样的错误。现在警报几乎每 1 分钟触发一次。
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