应用层唤醒/关闭屏幕

应用层唤醒屏幕及强制系统休眠

package com.example.hello;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.os.PowerManager;
import android.os.PowerManager.WakeLock;
import android.os.SystemClock;
import android.app.Activity;
import android.content.Context;
import android.util.Log;
import android.view.Menu;
public class MainActivity extends Activity {
 protected static final String TAG = "MainActivity";
 private Handler mHandler;
 PowerManager pm;
 WakeLock mWakeLock;
 PowerManager.WakeLock wl;
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        pm = (PowerManager)getSystemService(Context.POWER_SERVICE);
        	/*mWakeLock = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "WhatEver");
        	Log.v(TAG, "PARTIAL_WAKE_LOCK");
  	mWakeLock.acquire();*/
      	//Forces the device to go to sleep.
  	pm.goToSleep(SystemClock.uptimeMillis());
        mHandler = new Handler(){
   @Override
   public void handleMessage(Message msg) {
    Log.v(TAG, "handleMessage");
    switch(msg.what){
    case 1:
     wl = pm.newWakeLock(PowerManager.FULL_WAKE_LOCK |   //这个参数是手机点亮的程度，（什么Cpu，屏幕亮度，键盘灯），可以理解为通过Android组件（Activity）去点亮了屏幕。   
                      PowerManager.ACQUIRE_CAUSES_WAKEUP |    //不依赖组件就可以点亮屏幕了，比如在通知里需要点亮屏幕，需要加入这个参数   
                      PowerManager.ON_AFTER_RELEASE, TAG);  
     wl.acquire( 5 * 1000);  //release after 5 seconds   
     break;
    case 2:
     break;
     default:
      Log.v(TAG, "can't process");
    }
    
   }
         
        };
        mHandler.sendEmptyMessageDelayed(1, 5*1000);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }
    
}
唤醒屏幕是需要权限的，在AndroidManifest.xml请加入：

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

并且只有系统进程有加权限<uses-permission android:name="android.permission.DEVICE_POWER" />

android:sharedUserId="android.uid.system"