ios - 右 UIBarButton 未显示

Question

就像这段代码一样简单：

-(void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
// Inizializzazione barra di navigazione
[[self navigationController] setNavigationBarHidden:NO];

UINavigationItem* a = [self navigationItem];
[a setTitle:@"SOME TITLE"];
UIImage *background = [UIImage imageNamed:@"header.png"];
CGSize newSize;
newSize.height=100;
[self.navigationController.navigationBar setBackgroundImage:background 
                                         forBarMetrics:UIBarMetricsDefault];
UIBarButtonItem *rightButton = [[UIBarButtonItem alloc] 
                 initWithTitle:@"Homefgh"                                                                                  
                 style:UIBarButtonItemStyleBordered 
                 target:self action:@selector(home)];

self.navigationController.navigationItem.rightBarButtonItem = rightButton;
}

但未显示按钮（在右侧）。我还尝试将代码放在 viewDidLoad 中。viewWillAppear 位于主 UINavigationController 顶部的 UIView 内。奇怪的是背景图像正确显示。

Answer 1

你应该能够做一些像这样简单的事情来让它显示出来：

UIBarButtonItem *rightButton = [[UIBarButtonItem alloc] 
                 initWithTitle:@"Homefgh"                                                                                  
                 style:UIBarButtonItemStyleBordered 
                 target:self action:@selector(home)];

self.navigationItem.rightBarButtonItem = rightButton;

Answer 2

- (void)viewDidLoad {
  [super viewDidLoad];

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

记得把它放在 viewDidLoad 而不是 viewWillAppear 中。

Answer 3

在你的代码中添加这个

self.navigationItem.rightBarButtonItem = rightButton;

而不是这段代码

self.navigationController.navigationItem.rightBarButtonItem = rightButton;

并且会显示出来。

Answer 4

更改self.navigationController.navigationItem.rightBarButtonItem = rightButton;为self.navigationItem.rightBarButtonItem = rightButton;