Question

i am new into ObjC, unfortunately..

I have created a list and Tool bar at the bottom, with two buttons.

The first button does the list refresh,
the second one should be ‘enabled’ when you tap on a list item and when clicked it will perform additional work. This requires me to disable this button on start, but enable on didSelectRowAtIndexPath.

I want to grab a pointer to the second button on viewDidLoad method for later purposes.
Something like that would be great:

UIBarButtonItem* m_pButtonA = (UIBarButtonItem*) some_magic_function_to_call;
UIBarButtonItem* m_pButtonB = (UIBarButtonItem*) some_magic_function_to_call;

So i can later call the control method when required.

[m_pButtonRefresh method...]

Is this possible ? Thanks for any input.

Answer 1

In your custom view controller class, create an IBOutlet property, like this:

@property (nonatomic, weak) IBOutlet UIBarButtonItem* m_pButtonA;
@property (nonatomic, weak) IBOutlet UIBarButtonItem* m_pButtonB;

(I’d suggest using more descriptive names)

Then, in Interface Builder you can set those properties to be the Reference Outlet for each of those views (drag from the little (+) to the view control in the left sidebar in IB, and select the appropriate property).

You’ll then be able to access those items using code along the lines of self.m_pButtonA. You don’t need to manually create the reference to them, as the code will automatically generate them.

This is somewhat similar to the approach you would use when connecting GUI events to methods in the view controller (those would use methods labeled with type IBAction), that are triggered automatically when those events are raised. Both IBOutlet and IBAction are just little hints for Interface Builder (IBAction is actually just another name for void).