Android系统亮屏、锁屏、屏幕解锁事件(解决部分手机亮屏后未解锁即进入resume状态)

有一部分三星的手机关闭屏幕以后，刚打开屏幕，前台的activity就会resume状态，因为我们使用cocos2d-x引擎，默认resume和activity的resume事件是一致的，我们在resume里把关闭的声音重新打开，所以导致，用户点亮屏幕以后（尚未解锁），就会听到游戏内的声音（如果在关闭屏幕时我们游戏处于前台）。

为了解决这个问题，我们需要修改我们resume触发的时机。确保在解锁以后才进入我们游戏的resume状态。

那么我们游戏应该在什么时机进入resume状态呢？

1. 系统activity进入resume状态时刻，并且屏幕是亮的，屏幕未锁定
2. 屏幕刚刚亮起，并且屏幕 未锁定，系统activity已经进入resume状态
3. 屏幕 解锁，这是屏幕肯定是亮的，并且activity已经进入resume状态

那么有了上面的三点相信逻辑代码不难写，下面介绍一下如何坚挺系统屏幕灭，屏幕亮，解锁屏幕 的事件，以及如何判断当前屏幕 是否是解锁状态（因为用户可以设置关闭屏幕后是否锁定屏幕 ，所以解锁屏幕 事件可能根本就不会被触发，那么我们就不能通过跟踪事件来确定其状态）

要坚挺屏幕亮、屏幕灭、屏幕 解锁三个事件我们需要在代码中注册监听ACTION_SCREEN_ON、ACTION_SCREEN_OFF、ACTION_USER_PRESENT三个Action，具体的写法如下：

/** * screen状态广播接收者 */private class ScreenBroadcastReceiver extends BroadcastReceiver{@Overridepublic void onReceive(Context context, Intent intent) {if(Intent.ACTION_SCREEN_ON.equals(intent.getAction())){mScreenStateListener.onScreenOn();}else if(Intent.ACTION_SCREEN_OFF.equals(intent.getAction())){mScreenStateListener.onScreenOff();}else if(Intent.ACTION_USER_PRESENT.equals(intent.getAction())){mScreenStateListener.onUserPresent();}}}

/** * 停止screen状态更新 */public void stopScreenStateUpdate() {mContext.unregisterReceiver(mScreenReceiver);}/** * 启动screen状态广播接收器 */private void startScreenBroadcastReceiver() {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);}

因为屏幕在灭了以后是否锁定可以由用户设置，所以我们不能通过跟踪解锁事件来判断其状态，需要一个可以时时获取状态的函数：

//判断屏幕是否被锁定public final static boolean isScreenLocked(Context c) {android.app.KeyguardManager mKeyguardManager = (KeyguardManager) c.getSystemService(c.KEYGUARD_SERVICE);return mKeyguardManager.inKeyguardRestrictedInputMode();}

需要注意的是，大部分事件都可以在AndroidManifest.xml中注册，但是ACTION_SCREEN_ON、ACTION_SCREEN_OFF、ACTION_USER_PRESENT这几个事件在PowerManager那边做了限制，必须像上面那样在代码中注册，才能监听到，所以大家不要踩到坑哦~~~

下面是包装屏幕事件的一个类代码，仅供参考：

package com.example.myfirstapp;import java.lang.reflect.Method;import android.app.Activity;import android.app.KeyguardManager;import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;import android.content.IntentFilter;import android.os.PowerManager;import android.util.Log;/** * 监听屏幕ON和OFF PRESENT状态 *  * @author * @2014 *  */public class ScreenObserver {private static String TAG = "ScreenObserver";private Context mContext;private ScreenBroadcastReceiver mScreenReceiver;private ScreenStateListener mScreenStateListener;private static Method mReflectScreenState;public ScreenObserver(Context context) {mContext = context;mScreenReceiver = new ScreenBroadcastReceiver();try {mReflectScreenState = PowerManager.class.getMethod("isScreenOn",new Class[] {});} catch (Exception nsme) {Log.d(TAG, "API < 7," + nsme);}}/** * screen状态广播接收者 */private class ScreenBroadcastReceiver extends BroadcastReceiver {@Overridepublic void onReceive(Context context, Intent intent) {if (Intent.ACTION_SCREEN_ON.equals(intent.getAction())) {mScreenStateListener.onScreenOn();} else if (Intent.ACTION_SCREEN_OFF.equals(intent.getAction())) {mScreenStateListener.onScreenOff();} else if (Intent.ACTION_USER_PRESENT.equals(intent.getAction())) {mScreenStateListener.onUserPresent();}}}/** * 请求screen状态更新 */public void requestScreenStateUpdate(ScreenStateListener listener) {mScreenStateListener = listener;startScreenBroadcastReceiver();firstGetScreenState();}/** * 第一次请求screen状态 */private void firstGetScreenState() {PowerManager manager = (PowerManager) mContext.getSystemService(Activity.POWER_SERVICE);if (isScreenOn(manager)) {if (mScreenStateListener != null) {mScreenStateListener.onScreenOn();}} else {if (mScreenStateListener != null) {mScreenStateListener.onScreenOff();}}}/** * 停止screen状态更新 */public void stopScreenStateUpdate() {mContext.unregisterReceiver(mScreenReceiver);}/** * 启动screen状态广播接收器 */private void startScreenBroadcastReceiver() {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);}/** * screen是否打开状态 */private static boolean isScreenOn(PowerManager pm) {boolean screenState;try {screenState = (Boolean) mReflectScreenState.invoke(pm);} catch (Exception e) {screenState = false;}return screenState;}// 外部调用接口public interface ScreenStateListener {public void onScreenOn();public void onScreenOff();public void onUserPresent();}public final static boolean isScreenLocked(Context c) {android.app.KeyguardManager mKeyguardManager = (KeyguardManager) c.getSystemService(c.KEYGUARD_SERVICE);return mKeyguardManager.inKeyguardRestrictedInputMode();}}

上面代码参考：http://blog.csdn.net/m_changgong/article/details/7608911，特此注明。