packages\apps\Phone\src\com\android\phone\InCallScreen.java
1.添加全局聲明
private PowerManager.WakeLock mWakeLock;//soten cwb 2012/11/21
2.initInCallScreen方法的最後加上
//soten cwb 2012/11/21
mWakeLock = mPowerManager.newWakeLock(PowerManager.SCREEN_DIM_WAKE_LOCK, "My Tag");
3.在onResume方法的最後添加
//soten cwb 2012/11/21
mWakeLock.acquire();
4.在onPause方法的最後添加
//soten cwb 2012/11/21
mWakeLock.release();