如何通过复制现有的UIViewController来创建新的UIViewController？

Question

I want to create a new UIViewController that is very similar to an existing one. I tried copying the files (old.m, old.h, and old.xib) and renaming them (new.m, etc.) The results, when added to the project, compile just fine, but I have a problem in the implementation of initWithNibName;

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
        someCustomWork(); // Not important for the problem, but the reason for this function!
    }
    return self;
}

The call to the super initWithNibName always returns (null), where for the original, a valid object is returned.

So, what am I missing here? How can I best create a new UIViewController by copying the files of an existing one?

Thanks!

Answer 1

Heritage. Create a new blank VC and in the .h file:

#import "OldViewController.h"

@interface NewViewController : OldViewController

This will make the newVC have all the same functions and properties as the old one. Then override everything that must be different in the new one.

Not sure about the xib files, never worked with storyboards.