How to add image in UINavigationBar in IPhone app

Swift version: You can create a protocol extension for using the function in your view controllers

protocol Customizable {
    var navigationItem: UINavigationItem { get }
}

extension Customizable {
    func setNavBarLogo() {

        let logo = UIImage(named: "logo")
        let logoImageView = UIImageView(image: logo)

        self.navigationItem.titleView = logoImageView
    }
}

One way to do this is to use UINavigationItem.titleView and UINavigationItem.rightBarButtonItem. Like this :

viewController.navigationItem.titleView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"yourimage.png"]];
UIBarButtonItem * item = [[UIBarButtonItem alloc] initWithCustomView:[[UIImageView alloc] initWithImage:[UIImage imageNamed:@"yourimage2.jpg"]]];    
viewController.navigationItem.rightBarButtonItem = item;    

Here I am using UIImageView as custom view, but it can be UIButton with custom image.

Another way without using a viewController

// Create your image
UIImage *image = [UIImage imageNamed: @"logo.png"];
UIImageView *imageview = [[UIImageView alloc] initWithImage: image];

// set the image view to the title view
self.navigationItem.titleView = imageview;