Struct objc error in UIBarButton Class - iphone

Question

I wanted to create a barbutton that was a custom image so I created a subclass UIBarButtonItem.
#implementation UIBar
+ (UIBarButtonItem*)barItemWithImage:(UIImage*)image target:(id)target action:(SEL)action{
UIImage *menuButtonImage = [UIImage imageNamed:#"Camera.jpg"];
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
[button setImage:menuButtonImage forState:UIControlStateNormal];
button.frame = CGRectMake(0, 0, menuButtonImage.size.width, menuButtonImage.size.height);
UIBarButtonItem *menuButton = [[UIBarButtonItem alloc] initWithCustomView:button];
[button addTarget:self action:#selector(takePicture) forControlEvents:UIControlEventTouchUpInside];
// self->navigationItem.rightBarButtonItem = menuButton;
[UIViewController release];
}
But the error I'm getting on the line:
self.navigationItem.rightBarButtonItem = button;
incomplete definition of type struct objc_class
Does this error have anything to do with my class not being initialised properly? I'm new to Objective-C.
Thanks for your help.

Answer 1

In your category method, you are not returning any UIBarButtonItem instance. Try to return the menuButton.
And I am not sure why you need to call class method of UIViewController. The method is for instance, not a class method. Remove that line too.
+ (UIBarButtonItem*)barItemWithImage:(UIImage*)image target:(id)target action:(SEL)action{
UIImage *menuButtonImage = [UIImage imageNamed:#"Camera.jpg"];
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
[button setImage:menuButtonImage forState:UIControlStateNormal];
button.frame = CGRectMake(0, 0, menuButtonImage.size.width, menuButtonImage.size.height);
UIBarButtonItem *menuButton = [[UIBarButtonItem alloc] initWithCustomView:button];
[button addTarget:self action:#selector(takePicture) forControlEvents:UIControlEventTouchUpInside];
return menuButton;
}

Answer 2

If you want custom bar button then you can use the following code in your viewDidLoad method of viewController.
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
[button setImage:buttonImage forState:UIControlStateNormal];
button.frame = CGRectMake(0, 0, buttonImage.size.width, buttonImage.size.height);
[button addTarget:self action: #selector(takePicture)forControlEvents:UIControlEventTouchUpInside];
UIBarButtonItem *customBarItem = [[UIBarButtonItem alloc] initWithCustomView:button];
self.navigationItem.leftBarButtonItem = customBarItem;
If you want to subclass UIBarButtonItem then you can do the following.
#implementation UIBar
+ (UIBarButtonItem*)barItemWithImage:(UIImage*)image target:(id)target action:(SEL)action
{
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
[button setImage:image forState:UIControlStateNormal];
button.frame = CGRectMake(0, 0, image.size.width, image.size.height);
UIBarButtonItem *menuButton = [[UIBarButtonItem alloc] initWithCustomView:button];
[button addTarget:target action:action forControlEvents:UIControlEventTouchUpInside];
return menuButton;
}
and in your viewController viewDidLoad method do the following
UIBar *customBarItem = [UIBar barItemWithImage:buttonImage target:self action:#selector(takePicture)];
self.navigationItem.leftBarButtonItem = customBarItem;
Both the method will work.