Question

here is a quick question,
i have my couple view controllers classes, and have some other classes.
i’ve found my self creating some methods in all of their implementation files, which are doing the same.

i would like to write some of my methods in a seperate file,
and import this file into my view controllers.
therefore, i will be able to run those methods from my current view controller,

In case this method will require a change, i will not need to re-write it in all my implementaion files.

Let me Sharp just one thing. I do not want to create a new object! and instantiate it.
i do want to be able to run this method just like i was doing: [self doSomething];

Please help to understand how this should be done.

i.e.
i have 3 view controllers, each has the bellow method:

-(void)doSomething:(id)sender{
//doing something
}

just want to have this doSomething method defined in one place,
and i could access it from my view controllers by running:
[self doSomething];

is it possible?

Thanks in advance.

Answer 1

You want to do this by subclassing. First create a class where you want all your shared methods, as a subclass of UIViewController, let’s call it BaseViewController. For example you’d have this in your header file:

@interface BaseViewController: UIViewController 
{
}
-(void)doSomething:(id)sender;
@end

And then the corresponding definition in your .m file.

Now when you want to create a new UIViewController subclass which has the shared methods make the new class a subclass of BaseViewController not UIViewController, like so:

@interface MyViewController: BaseViewController
{
}
@end