首先找到对应长短按power键的位置：

frameworks\base\policy\src\com\android\internal\policy\impl\PhoneWindowManager.java

private final Runnable mPowerLongPress = new Runnable() {@Overridepublic void run() {// The context isn't readif (mLongPressOnPowerBehavior < 0) {mLongPressOnPowerBehavior = mContext.getResources().getInteger(com.android.internal.R.integer.config_longPressOnPowerBehavior);}int resolvedBehavior = mLongPressOnPowerBehavior;if (FactoryTest.isLongPressOnPowerOffEnabled()) {resolvedBehavior = LONG_PRESS_POWER_SHUT_OFF_NO_CONFIRM;}switch (resolvedBehavior) {case LONG_PRESS_POWER_NOTHING:break;case LONG_PRESS_POWER_GLOBAL_ACTIONS:mPowerKeyHandled = true;//<!-- $_rbox_$_modify_$_huangjc -->if("true".equals(SystemProperties.get("persist.sys.realsleep"))){showSleepDialog();} else {if (!performHapticFeedbackLw(null, HapticFeedbackConstants.LONG_PRESS, false)) {performAuditoryFeedbackForAccessibilityIfNeed();}sendCloseSystemWindows(SYSTEM_DIALOG_REASON_GLOBAL_ACTIONS);showGlobalActionsDialog();}break;case LONG_PRESS_POWER_SHUT_OFF:case LONG_PRESS_POWER_SHUT_OFF_NO_CONFIRM:mPowerKeyHandled = true;performHapticFeedbackLw(null, HapticFeedbackConstants.LONG_PRESS, false);sendCloseSystemWindows(SYSTEM_DIALOG_REASON_GLOBAL_ACTIONS);mWindowManagerFuncs.shutdown(resolvedBehavior == LONG_PRESS_POWER_SHUT_OFF);break;}}};

其中case LONG_PRESS_POWER_GLOBAL_ACTIONS: 对应的是长按， 而调用的方法showGlobalActionsDialog()就是处理弹窗的方法；

void showGlobalActionsDialog() {if (mGlobalActions == null) {mGlobalActions = new GlobalActions(mContext, mWindowManagerFuncs);}final boolean keyguardShowing = keyguardIsShowingTq();mGlobalActions.showDialog(keyguardShowing, isDeviceProvisioned());if (keyguardShowing) {// since it took two seconds of long press to bring this up,// poke the wake lock so they have some time to see the dialog.mPowerManager.userActivity(SystemClock.uptimeMillis(), false);}}

所以去掉showGlobalActionsDialog();就不会再有弹窗出现了；

如果要做短按power键使系统直接关机的这个功能，那么只需要在PhoneWindowManager.java中找到短按处理的代码，然后添加mWindowManagerFuncs.shutdown(true);就可以了。