Android:闹钟在预定时间之前被触发

Question

我试图在应用程序启动10分钟后生成警报。根据我的要求，这个警报应该工作，无论用户关闭应用程序，关闭并再次打开，甚至重启后。下面是我的代码。

MainActivity.java

import android.app.ActivityManager;
import android.app.Application;
import android.content.Context;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import java.util.List;
public class MainActivity extends AppCompatActivity {
    private Context context;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        this.context=this;
        startService(new Intent(getBaseContext(), MyService.class));
    }
    public void startService(View view) {
      //  startService(new Intent(getBaseContext(), MyService.class));
    }
    // Method to stop the service
    public void stopService(View view) {
      //  stopService(new Intent(getBaseContext(), MyService.class));
    }
}

MyService.java -这是服务类

import android.app.AlarmManager;
import android.app.IntentService;
import android.app.PendingIntent;
import android.app.Service;
import android.content.ComponentName;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.os.IBinder;
import android.os.SystemClock;
import android.widget.Toast;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Calendar;
import java.util.GregorianCalendar;
/**
 * Created by Nirodha Mihiran on 6/8/2016.
 */
public class MyService extends Service {
    public static boolean doneCreted = false;
    @Override
    public IBinder onBind(Intent arg0) {
        return null;
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        // Let it continue running until it is stopped.
        Toast.makeText(this, "Service Started Second", Toast.LENGTH_LONG).show();
        Calendar calendar = new GregorianCalendar();
        calendar.setTimeInMillis(System.currentTimeMillis() + 10 * 60 * 1000);
        intent = new Intent(MyService.this, AlarmReceiver.class);
        PendingIntent pendingIntent = PendingIntent.getBroadcast(MyService.this, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
        AlarmManager am = (AlarmManager) MyService.this.getSystemService(MyService.this.ALARM_SERVICE);
        // am.setRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), 1000 * 60 * 5, pendingIntent);
        // am.setWindow(AlarmManager.RTC_WAKEUP,calendar.getTimeInMillis(), 1000 * 60 * 5 , pendingIntent);
        am.set(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), pendingIntent);
        return START_STICKY;
    }
    @Override
    public void onDestroy() {
        super.onDestroy();
        Toast.makeText(this, "Service Destroyed", Toast.LENGTH_LONG).show();
    }
}

AlarmReciever.java

import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.media.RingtoneManager;
import android.net.Uri;
import android.support.v4.app.NotificationCompat;
import android.widget.Toast;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Calendar;
import java.util.GregorianCalendar;
/**
 * Created by thisararanawaka on 6/2/16.
 */
public class AlarmReceiver extends BroadcastReceiver {
    private int MID = 0;
    public static boolean isCreated;
    @Override
    public void onReceive(Context context, Intent intent) {
        // TODO Auto-generated method stub
        long when = System.currentTimeMillis();
        Calendar calendar = new GregorianCalendar();
        calendar.setTimeInMillis(System.currentTimeMillis()+5*60*1000);
        NotificationManager notificationManager = (NotificationManager) context
                .getSystemService(Context.NOTIFICATION_SERVICE);
        Intent notificationIntent = new Intent(context, MainActivity.class);
        notificationIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
        PendingIntent pendingIntent = PendingIntent.getActivity(context, 0,
                notificationIntent, PendingIntent.FLAG_UPDATE_CURRENT);
        Uri alarmSound = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
        NotificationCompat.Builder mNotifyBuilder = new NotificationCompat.Builder(
                context).setSmallIcon(R.mipmap.ic_launcher)
                .setContentTitle("Alaram Fired")
                .setContentText("Events To be Performed").setSound(alarmSound)
                .setAutoCancel(true)
                .setContentIntent(pendingIntent)
                .setVibrate(new long[]{1000, 1000, 1000, 1000, 1000});
        notificationManager.notify(MID, mNotifyBuilder.build());
        MID++;
        Toast.makeText(context, "Notification Created .", Toast.LENGTH_LONG).show();
    }
}

如果我没有关机和关机或重新启动手机，我在获得闹钟准时没有问题。我准时把闹钟响了。

然而，如果我关闭并打开手机，或者如果我重新启动手机，我就会在手机打开/重新启动后收到警报和通知-可能在一分钟后。在这种情况下，即使闹钟安排在明天也没关系，我一开机/重启手机就会收到。

我做错了什么?

Answer 1

通过查看您的代码，这可能是

在你的onStartCommand()中，你将时间设置为calendar.setTimeInMillis(System.currentTimeMillis() + 10 * 60 * 1000);

将日历时间设置为+ 10分钟，然后在下一行设置相同的时间am.set(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), pendingIntent);

试试这样，

long myAlarmTime = System.currentTimeMillis() + 10 * 60 * 1000;am.set(AlarmManager.RTC_WAKEUP, myAlarmTime, pendingIntent);

重新启动时遇到此问题的原因

服务可以被系统运行有两个原因。如果有人调用Context.startService()，那么系统将检索服务(创建它并在需要时调用它的onCreate()方法)，然后使用客户端提供的参数调用它的onStartCommand(Intent, int, int)方法。此时，服务将继续运行，直到Context.stopService()或stopSelf()被调用。https://developer.android.com/reference/android/app/Service.html