CODEWITHSUNDEEP
iosuinavigationcontrolleruinavigationitemios6.1
Ziv Levy
Ziv Levy

Reputation: 2044

UINavigationItem is not shown in my ViewController



I'm writing a simple app in iOS using Xcode, I'm trying to load another ViewController as a modal. The origin HomeScreenViewController (inherits from UIViewController) where I'm loading the modal is originated with the project's Storyboard.
Then, as a response to a button pressed event, I'm loading this modal like this:

-(IBAction)onAddButtonPressed:(UIButton *)sender {
    MyAnotherViewController *vc = [[MyAnotherViewController alloc] init];
    [self presentViewController:vc animated:YES completion:nil];
}

The class MyAnotherViewController is not represented in the Storyborad since its a simple class to show a navigation bar and a text field. The code is (partial code, the rest is Xcode auto-generated methods):

@implementation MyAnotherViewController 

- (void)viewDidLoad {
    [self.navigationItem setTitle:@"Example"];
    [self.view addSubview:[[UITextView alloc]initWithFrame:self.view.bounds]];
}
@end

The problem is (also can be seen in the attached image) that the navigationItem is not shown for some reason.
I also validated that self.navigationItem is not nil and it is not. Even more, I can see in debug mode that the title is actually set to "Example".

As can be seen in the screenshot, the UITextView captures the entire screen

Your help is well appreciated,
Cheers...

Upvotes: 0

Views: 2350

Answers (2)

liuyaodong
liuyaodong

Reputation: 2567

If your MyAnotherViewController is not a subclass of UINavigationController, or if you have not manually add an UINavigationItem, UIViewController cannot show a navigation item. Maybe you can try to wrap the MyAnotherViewController with an UINavigationController.

// Assume you have adopted ARC
-(IBAction)onAddButtonPressed:(UIButton *)sender {
    MyAnotherViewController *vc = [[MyAnotherViewController alloc] init];
    UINavigationController *nav = [[UINavigationController alloc] initWithRootViewController:vc];
    [self presentViewController:nav animated:YES completion:nil];
}

And in your -viewDidLoad of MyAnotherViewController, you just need to do this:

-(void)viewDidLoad {
    self.title = @"Example";
    /*
     * Your other code
     */
}

Upvotes: 0

Vinzzz
Vinzzz

Reputation: 11724

The UINavigationItem property of a UIViewController is only used when the ViewController is inside a UINavigationController, so : 

-(IBAction)onAddButtonPressed:(UIButton *)sender {
    MyAnotherViewController *vc = [[MyAnotherViewController alloc] init];
    UINavigationController *navCtl = [[UINavigationController alloc] initWithRootController:vc];
    [self presentViewController:navCtl animated:YES completion:nil];
}

Upvotes: 2

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