首先是一個封裝類

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狀態廣播接收者
     */
private class ScreenBroadcastReceiver 
 
extends BroadcastReceiver {
        @Override
public 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();
}
        }
    }

    /**
     * 請求screen狀態更新
     */
public void requestScreenStateUpdate(ScreenStateListener listener) {
        mScreenStateListener = listener;
startScreenBroadcastReceiver();
firstGetScreenState();
}

    /**
     * 第一次請求screen狀態
     */
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狀態更新
     */
public void stopScreenStateUpdate() {
        mContext.unregisterReceiver(mScreenReceiver);
}

    /**
     * 啟動screen狀態廣播接收器
     */
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是否開啟狀態
     */
private static boolean isScreenOn(PowerManager pm) {
        boolean screenState;
try {
            screenState = (Boolean) mReflectScreenState.invoke(pm);
} catch (Exception e) {
            screenState = false;
}
        return screenState;
}

    // 外部呼叫介面
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();
}
}

用法::::::::::::::::::::::::::::::::::::::::::::::::::::::::::在主的介面上

//訂閱
screenObserver.requestScreenStateUpdate(this);

//亮屏
@Override
public void onScreenOn() {
    Log.d("xxxxx", "亮屏");
}

//息屏
@Override
public void onScreenOff() {
    Log.d("xxxxx", "息屏");
}

//鎖屏
@Override
public void onUserPresent() {
    Log.d("xxxxx", "鎖屏");
}