I am (also) having trouble making connections between code and Interface Builder

Answer 1

In the sample (I just downloaded and opened), that button isn't connected to an IBAction on File's Owner (which in this case is a non-subclassed instance of UIApplication).

It is connected to an IBAction on the view controller for the "Local" tab. To re-create it:

• Open up MyOverlayView and TabBarController.
• Right-click on the rounded button in the MyOverlayView to bring up the connections inspector.
• Left-drag from the circle next to the "Touch up inside" event to the "Local" tab button in the TabBarController window. Interface Builder interprets this as you wanting to make a connection to the UIViewController subclass that is managing that tab - in this case MyMovieController.
• From the popup that appears when you release the mouse button, select the IBAction that you want to connect the event to. It was connected to the OverlayViewButtonPressed action. If you look at the code, that function does nothing, but you can put some stuff in there and amuse yourself. Or you could try creating an IBAction on the MoviePlayerAppDelegate and connecting the event there (in which case you would drag the connection to the "Movie Player App Delegate" icon in the MainWindow.xib window.

Hope that helps! :)