在Android系统中，长按Power键默认会弹出对话框让你选择“飞行模式”，“静音”，“关机”等功能,弹出对话框的代码位于：
frameworks\policies\base\phone\com\android\internal\policy\impl\PhoneWindowManager.java
Runnable mEndCallLongPress = new Runnable() {
public void run() {
mShouldTurnOffOnKeyUp = false;
performHapticFeedbackLw(null, HapticFeedbackConstants.LONG_PRESS, false);
sendCloseSystemWindows(SYSTEM_DIALOG_REASON_GLOBAL_ACTIONS);
showGlobalActionsDialog();
}
};
void showGlobalActionsDialog() {
if (mGlobalActions == null) {
mGlobalActions = new GlobalActions(mContext);
}
final boolean keyguardShowing = mKeyguardMediator.isShowing();
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.
mKeyguardMediator.pokeWakelock();
}
}
frameworks\policies\base\phone\com\android\internal\policy\impl\GlobalActions.java