使用唤醒锁

Question

我有一个睡眠机应用程序，如果手机进入待机状态，我仍想播放声音。我刚刚编辑了添加唤醒锁，它也被添加到清单中。它没有正常工作，但我不确定原因。

package com.androidsleepmachine.gamble;

import android.app.Activity; 
import android.content.Context;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.os.Handler;
import android.os.PowerManager;
import android.view.KeyEvent;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.Spinner;

public class Ship extends Activity implements View.OnClickListener {
public static final Integer[] TIME_IN_MINUTES = { 30, 45, 60, 180, 360 };
public MediaPlayer mediaPlayer;
public Handler handler = new Handler();
public Button button2;
public Spinner spinner2;
private PowerManager.WakeLock wl;
// Initialize the activity
@Override
public void onCreate(Bundle savedInstanceState) { 
super.onCreate(savedInstanceState);
    super.onCreate(savedInstanceState);
    setContentView(R.layout.ship);
     PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
     wl = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "DoNjfdhotDimScreen");


    button2 = (Button) findViewById(R.id.btn2);
    button2.setOnClickListener(this);
    spinner2 = (Spinner) findViewById(R.id.spinner2);
    ArrayAdapter<Integer> adapter = new ArrayAdapter<Integer>(this,   
android.R.layout.simple_spinner_item, TIME_IN_MINUTES);

adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);          
    spinner2.setAdapter(adapter); 
}

// Play the sound and start the timer
private void playSound(int resourceId) {
    // Cleanup any previous sound files
    cleanup();
    // Create a new media player instance and start it
    mediaPlayer = MediaPlayer.create(this, resourceId);
    mediaPlayer.start();
    // Create the timer to stop the sound after x number of milliseconds
    int selectedTime = TIME_IN_MINUTES[spinner2.getSelectedItemPosition()];
    handler.postDelayed(runnable, selectedTime * 60 * 1000);
}

// Handle button callback
@Override
public void onClick(View v) {
    switch (v.getId()) {
        case R.id.btn2:
            playSound(R.raw.ocean_ship);
            break;
    }
}
 protected void onStop()
  {

      cleanup();
      super.onStop();
  }
// Stop the sound and cleanup the media player
public void cleanup() {
    if (mediaPlayer != null) {
        mediaPlayer.stop();
        mediaPlayer.release();
        mediaPlayer = null;
         wl.release();
    }
    // Cancel any previously running tasks
    handler.removeCallbacks(runnable);
}

// Runnable task used by the handler to stop the sound
public Runnable runnable = new Runnable() {
    public void run() {
        cleanup();
    }
};
}

Answer 1

你可以通过唤醒锁来实现。它是Powermanager api。

的一部分

可以找到详细解释here.