UIBarButtonItem with custom image and no border

Another simple solution is

1. Drag a standard UIButton
2. Set the button's style to custom and set your image for that button
3. Drag it onto the UINavigationBar
4. Set Selector

You can add a method to UIBarButtonItem without subclassing it using custom category:

@interface UIBarButtonItem(MyCategory)

+ (UIBarButtonItem*)barItemWithImage:(UIImage*)image target:(id)target action:(SEL)action;

@end

@implementation UIBarButtonItem(MyCategory)

+ (UIBarButtonItem*)barItemWithImage:(UIImage*)image target:(id)target action:(SEL)action{
 // Move your item creation code here
}
@end

So anywhere in your code you can create bar item calling this method (provided that you include a header with its declaration).

P.S. You do not need to use 'v' UIView as you can create UIBarButtonItem with a button as custom view directly.
P.P.S. You also need [forward release] in your code.

I found it this ways easy. It is sugested on top. "random.png" has to be in project. Just drag and drop any image.

 UIButton *a1 = [UIButton buttonWithType:UIButtonTypeCustom];
        [a1 setFrame:CGRectMake(0.0f, 0.0f, 25.0f, 25.0f)];
        [a1 addTarget:self action:@selector(randomMsg) forControlEvents:UIControlEventTouchUpInside];
        [a1 setImage:[UIImage imageNamed:@"config.png"] forState:UIControlStateNormal];
        UIBarButtonItem *random = [[UIBarButtonItem alloc] initWithCustomView:a1];

 //? line incomplete ?//   imageNamed:@"random.png"] style:UIBarButtonItemStylePlain target:self action:@selector(randomMsg)];

    self.navigationItem.rightBarButtonItem = random;

An alternative is to subclass UIBarButtonItem. Why? So that the action is invoked on the target with the correct sender. In the code above, the sender argument in the action message is the UIButton instance, not the UIBarButtonItem instance. This would be important, for example, if you wish to present a UIPopoverController from the bar button item. By subclassing UIBarButtonItem, you can add an ivar that retains the original target, allowing our subclass instances to intercept, modify, and forward the action message with the proper sender.

So, CCFBarButtonItem.h:

#import <uIKit/UIBarButtonItem.h>

@interface CCFBarButtonItem : UIBarButtonItem
{
@protected
    id _originalTarget;
}
- (id)initWithImage:(UIImage *)image target:(id)target action:(SEL)action;
@end

and CCFBarButtonItem.m

#import "CCFBarButtonItem.h"
#import <UIKit/UIButton.h>
#import <UIKit/UIView.h>
#import <UIKit/UIImage.h>

@implementation CCFBarButtonItem

#pragma mark - Object life cycle

- (id)initWithImage:(UIImage *)image target:(id)target action:(SEL)action;
{
    _ASSIGN( _originalTarget, target );

    UIButton *imgButton = [UIButton buttonWithType:UIButtonTypeCustom];
    [imgButton setImage:image forState:UIControlStateNormal];
    imgButton.frame = CGRectMake(0.0, 0.0, image.size.width, image.size.height);
    [imgButton addTarget:self action:action forControlEvents:UIControlEventTouchUpInside];

    self = [super initWithCustomView:imgButton];

    return self;
}

- (void)dealloc;
{
    MCRelease(_originalTarget);
    [super dealloc];
}

- (NSMethodSignature *)methodSignatureForSelector:(SEL)aSelector;
{
    if( [_originalTarget respondsToSelector:aSelector] )
    {
        return [_originalTarget methodSignatureForSelector:aSelector];
    }
    else
    {
        return [super methodSignatureForSelector:aSelector];
    }
}

- (void)forwardInvocation:(NSInvocation *)anInvocation;
{
    SEL aSelector = [anInvocation selector];
    if( [_originalTarget respondsToSelector:aSelector] )
    {
        //  modify the 'sender' argument so that it points to self
        [anInvocation setArgument:&self atIndex:2];
        [anInvocation invokeWithTarget:_originalTarget];
    }
    else
    {
        [self doesNotRecognizeSelector:aSelector];
    }
}
@end