关于PhoneWindowManager处理keycode return 值问题

/**
* Called from the input dispatcher thread before a key is dispatched to a window.
*
*

Allows you to define
* behavior for keys that can not be overridden by applications.
* This method is called from the input thread, with no locks held.
*
* @param win The window that currently has focus. This is where the key
* event will normally go.
* @param event The key event.
* @param policyFlags The policy flags associated with the key.
* @return 0 if the key should be dispatched immediately, -1 if the key should
* not be dispatched ever, or a positive value indicating the number of
* milliseconds by which the key dispatch should be delayed before trying
* again.
*/
public long interceptKeyBeforeDispatching(WindowState win, KeyEvent event, int policyFlags);