Android实现屏幕保持常亮功能

PowerManager powerManager = (PowerManager)getSystemService(POWER_SERVICE);
if (powerManager != null) {
         wakeLock = powerManager.newWakeLock(PowerManager.FULL_WAKE_LOCK, "WakeLock");
 　　　　 wakeLock.acquire();  //开启屏幕常亮
 　　　　//wakeLock.release();  //释放wakeLock,注意此方法可能出现异常.具体可看源码
 }

mediaPlayer.setScreenOnWhilePlaying(true);

/**
  * Control whether we should use the attached SurfaceHolder to keep the
  * screen on while video playback is occurring.  This is the preferred
  * method over {@link #setWakeMode} where possible, since it doesn't
  * require that the application have permission for low-level wake lock
  * access.
  *
  * @param screenOn Supply true to keep the screen on, false to allow it
  * to turn off.
  */
 public void setScreenOnWhilePlaying(boolean screenOn) {
     if (mScreenOnWhilePlaying != screenOn) {
         if (screenOn && mSurfaceHolder == null) {
             Log.w(TAG, "setScreenOnWhilePlaying(true) is ineffective without a SurfaceHolder");
         }
         mScreenOnWhilePlaying = screenOn;
         updateSurfaceScreenOn();
     }
 }
　　......

 private void updateSurfaceScreenOn() {
     if (mSurfaceHolder != null) {　　　　　　  
         mSurfaceHolder.setKeepScreenOn(mScreenOnWhilePlaying && mStayAwake);   
     }
 }

/**
* 是否开启屏幕常亮
 */
private var enableKeepScreenOn = false

/**
 * activity 生命周期监听器
 */
private var mActivityLifecycleCallbacks = object : Application.ActivityLifecycleCallbacks {
    override fun onActivityCreated(activity: Activity, savedInstanceState: Bundle?) {
        //在activity创建的时候设置屏幕保持常亮
        if (enableKeepScreenOn) {
            activity.window.addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON)
        }
    }

    override fun onActivityStarted(activity: Activity) {
    }

    override fun onActivityResumed(activity: Activity) {
    }

    override fun onActivityPaused(activity: Activity) {
    }

    override fun onActivityStopped(activity: Activity) {
    }

    override fun onActivitySaveInstanceState(activity: Activity, outState: Bundle) {
    }

    override fun onActivityDestroyed(activity: Activity) {
    }

}

/**
 * 设置保持屏幕常亮状态
 */
fun setKeepScreenOn(enable: Boolean) {
    enableKeepScreenOn = enable
}