当我们在玩游戏或者看视频的时候不希望app黑屏，那么就需要在app使用的时候处于常量状态。
1、使用PowerManager.WakeLock
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
}2、MediaPlayer有自带的方法防止屏幕黑屏
mediaPlayer.setScreenOnWhilePlaying(true);
源码如下：
/**
* 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);
}
}3、在view中设置
setKeepScreenOn(true/false)，同样可以在xml中设置android:keepScreenOn=""，只要View可见即生效。
4、通过添加flag的方法设置
/**
* 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
}
