set a Global shortcut for my Application?
 

I write an App with qt4 Library!
and I need to set a global shortcut for my App!
how can I do this??
in qt way?
or another way??

What do you mean by "global shortcut"? You can define a symlink for any application, and that symlink can be accessed by anyone with proper privileges.

If you are referring to the analog of a Windows shortcut icon, then that would mean you want something analogous to the Windows "default" folder for desktop icons. There is not one by default in Linux, though you could undoubtedly create one by configuring a script to do that on user login.

My App work on background (stay in systray!)
and i want a way to call my App to do some work!!
a signal event or ... with a shortcut on keyboard! like Ctrl+F12 !!!