如何在UINavigationController中添加向右按钮?

Question

想要在navigation controller 的顶端条添加一个刷新键。不知道为什么不执行。
hearder代码：

@interface PropertyViewController : UINavigationController {}

添加button代码：

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
    if (self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]) {
        UIBarButtonItem *anotherButton = [[UIBarButtonItem alloc] initWithTitle:@"Show" style:UIBarButtonItemStylePlain
                target:self action:@selector(refreshPropertyList:)];        
        self.navigationItem.rightBarButtonItem = anotherButton;
    }
    return self;
}

不知道错误在哪儿，多谢指教

Answer 1

试试在viewDidLoad中实现。一般来说，代码都应该写在这个函数里面，因为一个UIViewController在初始化了之后并不一定会显示出来，在这种情况下viewDidLoad是不会被调用的

- (void)viewDidLoad {
  [super viewDidLoad];

  UIBarButtonItem *anotherButton = [[UIBarButtonItem alloc] initWithTitle:@"Show" style:UIBarButtonItemStylePlain target:self action:@selector(refreshPropertyList:)];          
  self.navigationItem.rightBarButtonItem = anotherButton;
  [anotherButton release];
}

 self.navigationItem.rightBarButtonItem= anotherButton; [anotherButton release];}