为什么我的UIBarButtonItem没有出现在右上角？

Question

我在.m中有这个代码的UIViewController:

@property (nonatomic,strong) IBOutlet UINavigationBar *navBar;
@property (nonatomic,strong) IBOutlet UIBarButtonItem *button;

@end

@implementation DetailViewController

    - (void)viewDidLoad{
    [super viewDidLoad];
    // Do any additional setup after loading the view.

    UIBarButtonItem *listoButton = [[UIBarButtonItem alloc] initWithImage:[UIImage imageNamed:@"ListoBtn1.png"] style:UIBarButtonItemStyleBordered target:self action:@selector(done:)];

    self.navBar.topItem.rightBarButtonItem = listoButton;

    //self.navBar.topItem.backBarButtonItem = self.button;
    [self setVariables];

}

按钮出现但看起来像这样:

我只是希望我的图像出现,而不是后退按钮.如何删除边框？

Answer 1

首先,NIB在您创建按钮时尚未完成加载initWithNibName,其次,您UINavigationBar不会自动使用navigationItem(它由导航控制器自动使用).如果你想添加按钮,navBar你应该这样做viewDidLoad.