Something like this? I can't remember where I found this code but I used it to toggle the on-screen keyboard because it would be hidden by default if a bluetooth one was connected.
- (void) toggleKeyboard(UIKeyboardImpl * keyImpl){
if (UIKeyboardAutomaticIsOnScreen()) {
UIKeyboardOrderOutAutomatic();
} else {
UIKeyboardOrderInAutomatic();
}
Edit
I found where I got this code from. It works fine but the catch is that you need to import the private framework GraphicsServices, which would most likely get your app rejected from the App store.