android - 通过android中的服务播放闹钟

Question

我是 android 的新手。我想在用户设置的时间到达时播放闹钟。我有闹钟 Activity 。代码如下:

Intent intent = new Intent(this, AlarmReciever.class);
PendingIntent pendingIntent = PendingIntent.getActivity(this,
    12345, intent, PendingIntent.FLAG_CANCEL_CURRENT);
AlarmManager am=(AlarmManager)getSystemService(ALARM_SERVICE);
am.set(AlarmManager.RTC_WAKEUP, (cal.getTimeInMillis()/1000)+(t*60*60),
        pendingIntent);//t is the time which is contained in database 

我的警报接收器 Activity 是这样的:

公共(public)类 AlarmReciever 扩展 Activity {

    private MediaPlayer mMediaPlayer;

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        this.requestWindowFeature(Window.FEATURE_NO_TITLE);
        this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
                WindowManager.LayoutParams.FLAG_FULLSCREEN);
        setContentView(R.layout.alarmrecieve);

        Button stopAlarm = (Button) findViewById(R.id.stopAlarm);
        stopAlarm.setOnTouchListener(new View.OnTouchListener() {

            @Override
            public boolean onTouch(View v, MotionEvent event) {
                // TODO Auto-generated method stub
                mMediaPlayer.stop();
                finish();
                return false;
            }
        });
        playSound(this, getAlarmUri());
    }

    private void playSound(Context context, Uri alert) {
        mMediaPlayer = new MediaPlayer();
        try {
            mMediaPlayer.setDataSource(context, alert);
            final AudioManager audioManager = (AudioManager) context
                    .getSystemService(Context.AUDIO_SERVICE);
            if (audioManager.getStreamVolume(AudioManager.STREAM_ALARM) != 0) {
                mMediaPlayer.setAudioStreamType(AudioManager.STREAM_ALARM);
                mMediaPlayer.prepare();
                mMediaPlayer.start();
            }
        } catch (IOException e) {
            System.out.println("OOPS");
        }
    }

        //Get an alarm sound. Try for an alarm. If none set, try notification,
        //Otherwise, ringtone.
    private Uri getAlarmUri() {
        Uri alert = RingtoneManager
                .getDefaultUri(RingtoneManager.TYPE_ALARM);
        if (alert == null) {
            alert = RingtoneManager
                    .getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
            if (alert == null) {
                alert = RingtoneManager
                        .getDefaultUri(RingtoneManager.TYPE_RINGTONE);
            }
        }
        return alert;
    }
}

我的问题是，当用户输入时间时，警报 Activity 应该在后台运行。当时间到达时，警报应该启动。我听说过服务。但我不知道它在我的项目中的实现。谢谢提前

Answer 1

是的，您可以使用服务。 See here .并通过pending intent启动Service。而不是这样的 Activity

PendingIntent pendingIntent = PendingIntent.getService(this,12345, intent,PendingIntent.FLAG_CANCEL_CURRENT);

示例:

Intent myIntent = new Intent(Add.this, MyAlarmService.class);
        PendingIntent   pendingIntent = PendingIntent.getService(this, 12345, myIntent, 0);

你的服务类将是这样的:

import java.util.Calendar;

import android.app.Service;
import android.content.Intent;
import android.database.Cursor;
import android.os.IBinder;
import android.util.Log;
import android.widget.Toast;

    public class MyAlarmService extends Service {


    @Override

    public void onCreate() {

    // TODO Auto-generated method stub

    //Toast.makeText(this, "MyAlarmService.onCreate()", Toast.LENGTH_LONG).show();

    }

   @Override

    public IBinder onBind(Intent intent) {

    // TODO Auto-generated method stub

    Toast.makeText(this, "MyAlarmService.onBind()", Toast.LENGTH_LONG).show();

    return null;

    }
     @Override

    public void onDestroy() {

    // TODO Auto-generated method stub

    super.onDestroy();

    Toast.makeText(this, "MyAlarmService.onDestroy()", Toast.LENGTH_LONG).show();

    }
    @Override

    public void onStart(Intent intent, int startId) {

    // TODO Auto-generated method stub

    super.onStart(intent, startId);

    Intent dialogIntent = new Intent(getBaseContext(),AlarmReciever.class);
    dialogIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    getApplication().startActivity(dialogIntent);

    }

    }
    @Override

    public boolean onUnbind(Intent intent) {

    // TODO Auto-generated method stub

    Toast.makeText(this, "MyAlarmService.onUnbind()", Toast.LENGTH_LONG).show();

    return super.onUnbind(intent);

    }        

    }

在服务中，调用你的 Activity AlarmReciever