首先,在Activity里添加一下代码：

成员变量：
private PowerManager.WakeLock wakeLock = null; 
 
 
重写父类Activity的两个方法并添加一下逻辑：
 
@Override  
    public void onResume() {
        super.onResume();    
        acquireWakeLock(this);  
         
    }  
   
    @Override  
    public void onPause() {  
        super.onPause();  
        releaseWakeLock();  
         
    }  
   
 
    public void acquireWakeLock(Context context) {  
        if (wakeLock == null) {  
            PowerManager powerManager = (PowerManager) (context  
                    .getSystemService(Context.POWER_SERVICE));  
            wakeLock = powerManager.newWakeLock(  
                    PowerManager.SCREEN_DIM_WAKE_LOCK, "My Tag");  
            wakeLock.acquire();  
        }  
    }  
   
 
    public void releaseWakeLock() {  
        if (wakeLock != null && wakeLock.isHeld()) {  
            wakeLock.release();  
            wakeLock = null;  
        }  
    }

然后，在AndroidManifest.xml里添加如下权限即可：

  <uses-permission android:name="android.permission.WAKE_LOCK" />