Question

I’ve got a UIViewController called “MainViewController” which uses a custom class ‘CustomController’ to control one of it’s sub-views. The custom class instantiates UIButtons in code. How would I get these buttons to trigger methods in the MainViewController?

Answer 1

I think delegation is the way to go there.

1. Define the protocol CustomControllerDelegate inside CustomController.h with a method like this for example:

   - (void) customControllerButtonPressed(id)sender; // BTW: you can use `CustomController` instead of `id` if you make a forward declaration for this class
   

2. Add a delegate property and synthesize it in the .m file

   @property (assign) id<CustomControllerDelgate> delegate;
   

3. Now when your button is pressed you simply call the delegate:

   [self.delegate customControllerButtonPressed:self];
   

4. In your MainViewController you make it conform to the specified protocol and set the CustomControllers delegate like so:

   CustomViewController *customVC = [[CustomViewController alloc] init];
   customVC.delegate = self;
   

5. Now when the button is pressed, the MainViewController‘s implementation of the specified method is called.