How to add a right bar button to a navigation bar in iphone

I want to add a right bar button item to the navigation bar, so that on click, it performs certain a function.

I have created the following code to add the right bar button item, but after it is done, the bar button item is not getting displayed in navigation bar:

-(void)viewDidload{
    self.navigationItem.rightBarButtonItem = 
    [[[UIBarButtonItem alloc] 
           initWithBarButtonSystemItem:UIBarButtonSystemItemAdd                                                                                                     
                   开发者_开发知识库             target:self
                                action:@selector(Add:)] autorelease];    
}

-(IBAction)Add:(id)sender
{
    TAddNewJourney *j=[[TAddNewJourney alloc]init];
    [app.navigationController pushViewController:j animated:YES];
    [j release];
}

Let assume, you have a UIViewController, like this:

UIViewController *vc = [UIViewController new];

And you added it to navigation controller:

UINavigationController *nc = [[UINavigationController alloc] initWithRootViewController:vc];

In this way rightBarButtonItem will NOT getting displayed:

nc.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"xyz" style:UIBarButtonItemStyleDone target:self action:@selector(xyz)];

BUT this way IT WILL appear:

vc.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"xyz" style:UIBarButtonItemStyleDone target:self action:@selector(xyz)];

Use your own viewcontroller instead of the navigationcontroller to refer navigationItem.

-(void)viewDidLoad
{ 
    [super viewDidLoad];
    app.navigationController.navigationItem.rightBarButtonItem = [[[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(Add:)] autorelease];
}

-(IBAction)Add:(id)sender
{
    TAddNewJourney *j=[[TAddNewJourney alloc]init];
    [app.navigationController pushViewController:j animated:YES];
    [j release];
}

Try the other answers. I posted this answer so that it will work if your viewcontroller does not have a navigation controller which i think is the problem.

Add this code in viewdidload

UIBarButtonItem *chkmanuaaly = [[UIBarButtonItem alloc]initWithTitle:@"Calculate" style:UIBarButtonItemStylePlain target:self action:@selector(nextview:)];

self.navigationItem.rightBarButtonItem = chkmanuaaly;

Most of the answers here address setting the UINavigationBar's rightBarButtonItem from within the new VC after it is shown. My need, which was actually answered by János, is to set the UINavigationItem items from the CALLING UIViewController. Hence, the following code (Thanks, János).

// from within self (aka the calling controller):

    UIViewController *c = [[[UIViewController alloc] init...] autorelease];
    c.navigationItem.rightBarButtonItem = [[[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(dismissModalViewControllerAnimated:)] autorelease];
    c.navigationItem.title = @"Title Goes Here";
    UINavigationController *nav = [[[UINavigationController alloc] initWithRootViewController:c] autorelease];
    nav.navigationBarHidden = FALSE;
    [self presentModalViewController:nav animated:YES];

Now, granted, this may seem redundant to János' answer, but I need more rep points in order o mark his response up. ;-)

UIBarButtonItem *add=[[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(addUser)];
    self.navigationItem.rightBarButtonItem=add;
    [add release];

I guess it will be more complete response and it should help in any situation:

-(void)viewDidLoad{

    //Set Navigation Bar
    UINavigationBar *navBar = [[UINavigationBar alloc] initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, 64)];

    //Set title if needed
    UINavigationItem * navTitle = [[UINavigationItem alloc] init];
    navTitle.title = @"Title";

    //Here you create info button and customize it
    UIButton * tempButton = [UIButton buttonWithType:UIButtonTypeInfoLight];

    //Add selector to info button
    [tempButton addTarget:self action:@selector(infoButtonClicked) forControlEvents:UIControlEventTouchUpInside];

    UIBarButtonItem * infoButton = [[UIBarButtonItem alloc] initWithCustomView:tempButton];

    //In this case your button will be on the right side
    navTitle.rightBarButtonItem = infoButton;

    //Add NavigationBar on main view
    navBar.items = @[navTitle];
    [self.view addSubview:navBar];

}

Use the following code:

    UIBarButtonItem *add=[[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(addUser)];
    self.navigationItem.rightBarButtonItem=add;
    [add release];

Hope this helps you out.

Enjoy!

Swift:

let rightButton = UIBarButtonItem(image: UIImage(named: "imageName"),
                                  style: .plain,
                                 target: self,
                                 action: #selector(buttonTapped))
navigationItem.setRightBarButton(rightButton, animated: false)

@objc func buttonTapped(sender: UIBarButtonItem!) {
    // Implement action 
}

UIButton *dButton=[UIButton buttonWithType:0];
dButton.frame=CGRectMake(50,50,50,50);

[dButton addTarget:self  action:@selector(clickdButton:)
  forControlEvents:UIControlEventTouchUpInside];
[dButton setImage:[UIImage imageNamed:@"iconnavbar.png"]
         forState:UIControlStateNormal];    
dButton.adjustsImageWhenHighlighted=NO;
dButton.adjustsImageWhenDisabled=NO;
dButton.tag=0;
dButton.backgroundColor=[UIColor clearColor];

UIBarButtonItem *RightButton=[[[UIBarButtonItem alloc] initWithCustomView:dButton]autorelease];
self.navigationItem.rightBarButtonItem=RightButton;

and then:

-(IBAction)clickdButton:(id)sender{
    classexample *tempController=[[classexample alloc] init];
    [self.navigationController pushViewController:tempController animated:YES];
    [tempController autorelease];
}