如何将 AlarmManager 附加到 BootReceiver

Posted 2023-03-07

【中文标题】如何将 AlarmManager 附加到 BootReceiver

【英文标题】：How to attach an AlarmManager to a BootReceiver

【发布时间】：2012-10-10 13:11:24

【问题描述】：

我在一个活动中有以下内容，它基本上在用户登录应用程序时设置了一个 AlarmManager。然后，AlarmManager 会定期调用另一个从手机数据库中删除事务的活动。这一切都很好。

// get a Calendar object with current time
Calendar cal = Calendar.getInstance();
// add 5 minutes to the calendar object
cal.add(Calendar.MINUTE, 1);
Intent intent = new Intent(EntryActivity.this, AlarmReceiver.class);
intent.putExtra("alarm_message", "deleting transactions");
// In reality, you would want to have a static variable for the request code instead of 192837
PendingIntent sender = PendingIntent.getBroadcast(EntryActivity.this, 192837,
                                    intent, PendingIntent.FLAG_UPDATE_CURRENT);
// Get the AlarmManager service
AlarmManager am = (AlarmManager) getSystemService(ALARM_SERVICE);
//am.set(AlarmManager.RTC_WAKEUP, cal.getTimeInMillis(), sender);
am.setRepeating(AlarmManager.RTC_WAKEUP, cal.getTimeInMillis(), 15000, sender);

.

public class AlarmReceiver extends BroadcastReceiver 

    @Override
    public void onReceive(Context context, Intent intent) 
        try 
            Bundle bundle = intent.getExtras();
            String message = bundle.getString("alarm_message");
            Toast.makeText(context, message, Toast.LENGTH_SHORT).show();
            Intent myIntent = new Intent(context, SendOutstandingTransactions.class);
            myIntent.setAction("com.carefreegroup.startatboot.MyService");
            context.startService(myIntent);
         catch (Exception e) 
            Toast.makeText(context, "There was an error somewhere, but we still"
                            + " received an alarm", Toast.LENGTH_SHORT).show();
            e.printStackTrace();
        
    

.

public class SendOutstandingTransactions extends IntentService 

    private static final String TAG = SendOutstandingTransactions.class.getSimpleName();
    NfcScannerApplication nfcscannerapplication;
    Cursor c;

    @Override
    public void onCreate() 
        nfcscannerapplication = (NfcScannerApplication)getApplication();
        super.onCreate();
    

    @Override
    protected void onHandleIntent(Intent intent) 
        nfcscannerapplication.loginValidate.deleteTableTransactions();
    

    public SendOutstandingTransactions() 
        super("SendOutstandingTransactions");
    
// end of class

仅在用户首次登录应用时才会调用定期删除事务的服务。从那时起它无限期地运行。如果用户重启手机怎么办？服务只会在用户下次登录时恢复。

我有一个 BootReceiver，但我不知道如何附加 AlarmManager。我尝试了以下方法，但 ALARM_SERVICE 无法解决。这是在正确的线路上吗？

public class MyBootReceiver extends BroadcastReceiver 

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

        //  Intent myIntent = new Intent(context, SendOutstandingTransactions.class);
        //  myIntent.setAction("com.carefreegroup.startatboot.MyService");
        //  context.startService(myIntent);

        // get a Calendar object with current time
        Calendar cal = Calendar.getInstance();
        // add 5 minutes to the calendar object
        cal.add(Calendar.MINUTE, 1);
        Intent intent = new Intent(MyBootReceiver.this, AlarmReceiver.class);
        intent.putExtra("alarm_message", "deleting transactions");
        // In reality, you would want to have a static variable for the request code instead of 192837
        PendingIntent sender = PendingIntent.getBroadcast(context, 192837,
                                    intent, PendingIntent.FLAG_UPDATE_CURRENT);
        // Get the AlarmManager service
        AlarmManager am = (AlarmManager) getSystemService(ALARM_SERVICE);
        //am.set(AlarmManager.RTC_WAKEUP, cal.getTimeInMillis(), sender);
        am.setRepeating(AlarmManager.RTC_WAKEUP, cal.getTimeInMillis(), 15000, sender);
    

【问题讨论】：

引导接收器？你的意思是广播接收器。

@PoweRoy 是的，很抱歉接收系统启动的 BroadcastReceiver

add 5 minutes to the calendar object ?你的意思是 1 分钟？

【参考方案1】：

getSystemService 可通过Context 获得。 （您在onReceive 收到它）

你应该这样做：

AlarmManager am = (AlarmManager) context.getSystemService(context.ALARM_SERVICE);

【讨论】：

我已将其更改为您建议的内容，但不幸的是 ALARM_SERVICE 仍然无法恢复

你还需要Context.ALARM_SERVICE

不，但我已将其更改为 Context.ALARM_SERVICE，它似乎就是这样。现在就去试试。