Question

android开发中如何捕捉自动休眠灰屏的这个事件？

休眠的过程是屏幕先变灰再变黑，想要实现在自动休眠灰屏时，点击后（屏幕会变亮）实现一些操作。
试了以下两种方案：
1、注册SCREEN_BRIGHTNESS广播，尝试获取屏幕的变化，无果，应该是android自身没有发送对应的广播消息
2、点击时获取系统的亮度值，（通过oldBrightness = getInt(getContentResolver(), SCREEN_BRIGHTNESS);）但发现还是255，即还是亮，所以无法判断。

所以想问下有没有其他方法，还是我的实现有问题？

Answer 1

　　捕捉自动休眠灰屏的事件，可以通过监听系统的广播获得当前手机屏幕的状态，广播需要在注册文件中注册，具体的实现代码如下：

　　public class ScreenListener {
private Context mContext;
private ScreenBroadcastReceiver mScreenReceiver;
private ScreenStateListener mScreenStateListener;

public ScreenListener(Context context) {
mContext = context;
mScreenReceiver = new ScreenBroadcastReceiver();
}

/**
* screen状态广播接收者
*/
private class ScreenBroadcastReceiver extends BroadcastReceiver {
private String action = null;

@Override
public void onReceive(Context context, Intent intent) {
action = intent.getAction();
if (Intent.ACTION_SCREEN_ON.equals(action)) { // 开屏
mScreenStateListener.onScreenOn();
} else if (Intent.ACTION_SCREEN_OFF.equals(action)) { // 锁屏
mScreenStateListener.onScreenOff();
} else if (Intent.ACTION_USER_PRESENT.equals(action)) { // 解锁
mScreenStateListener.onUserPresent();
}
}
}

/**
* 开始监听screen状态
*
* @param listener
*/
public void begin(ScreenStateListener listener) {
mScreenStateListener = listener;
registerListener();
getScreenState();
}

/**
* 获取screen状态
*/
private void getScreenState() {
PowerManager manager = (PowerManager) mContext
.getSystemService(Context.POWER_SERVICE);
if (manager.isScreenOn()) {
if (mScreenStateListener != null) {
mScreenStateListener.onScreenOn();
}
} else {
if (mScreenStateListener != null) {
mScreenStateListener.onScreenOff();
}
}
}

/**
* 停止screen状态监听
*/
public void unregisterListener() {
mContext.unregisterReceiver(mScreenReceiver);
}

/**
* 启动screen状态广播接收器
*/
private void registerListener() {
IntentFilter filter = new IntentFilter();
filter.addAction(Intent.ACTION_SCREEN_ON);
filter.addAction(Intent.ACTION_SCREEN_OFF);
filter.addAction(Intent.ACTION_USER_PRESENT);
mContext.registerReceiver(mScreenReceiver, filter);
}

public interface ScreenStateListener {// 返回给调用者屏幕状态信息
public void onScreenOn();

public void onScreenOff();

public void onUserPresent();
}
}

　　在上面的代码中,用到了动态注册广播,在需要监听屏幕状态的activity中,当不需要监听的时候,如activity finish的时候,使用unregisterListener解除广播监听;
下面是在Activity中调用;
　　ScreenListener l = new ScreenListener(this);
l.begin(new ScreenStateListener() {

@Override
public void onUserPresent() {
Log.e("onUserPresent", "onUserPresent");
}

@Override
public void onScreenOn() {
Log.e("onScreenOn", "onScreenOn");
}

@Override
public void onScreenOff() {
Log.e("onScreenOff", "onScreenOff");
}
});

　　通过以上步骤即实现了对屏幕状态的监听.

Answer 2

系统会发送广播
Intent.ACTION_SCREEN_OFF

Intent.ACTION_SCREEN_ON

Intent.ACTION_USER_PRESENT

blog.csdn.net/mengweiqi33/article/details/18094221