Android保持屏幕常亮

package com.hebaijun.wakelock; import android.app.Activity; import android.os.Bundle; import android.os.PowerManager; public class WakeLockActivity extends Activity {  PowerManager.WakeLock wakeLock;  /** Called when the activity is first created. */  @Override  public void onCreate(Bundle savedInstanceState) {   super.onCreate(savedInstanceState);   setContentView(R.layout.main);   wakeLock = ((PowerManager)getSystemService(POWER_SERVICE)).newWakeLock(PowerManager.SCREEN_BRIGHT_WAKE_LOCK | PowerManager.ON_AFTER_RELEASE, "WakeLockActivity");  }  @Override  protected void onPause() {   super.onPause();   if (wakeLock != null) {    wakeLock.release();   }  }  @Override  protected void onResume() {   super.onResume();   wakeLock.acquire();  } }