基于导航的模板存在问题

Question

大家好，

我正在创建一个基于导航的应用程序我正在以编程方式设计屏幕，我需要有 2 个栏按钮，即左栏按钮项目和左栏按钮项目。右栏按钮项目，所以我在 - (void)loadView 方法中使用了以下代码，但是当控制器进入 loadview 方法时它崩溃了，谁能告诉我这段代码出了什么问题，提前谢谢

  self.title = @"Add Item";
 self.navigationItem.leftBarButtonItem = [[[UIBarButtonItem alloc] 
 initWithBarButtonSystemItem:UIBarButtonSystemItemCancel 
 target:self action:@selector(cancel_Clicked:)] autorelease];

 self.navigationItem.rightBarButtonItem = [[[UIBarButtonItem alloc] 
 initWithBarButtonSystemItem:UIBarButtonSystemItemSave 
 target:self action:@selector(save_Clicked:)] autorelease];
 self.view.backgroundColor = [UIColor groupTableViewBackgroundColor];

Answer 1

试试这个代码

UIBarButtonItem *flipButton = [[UIBarButtonItem alloc] 
                           initWithTitle:@"Flip"                                            
                           style:UIBarButtonItemStyleBordered 
                           target:self 
                           action:@selector(flipView)];
self.navigationItem.rightBarButtonItem = flipButton;
[flipButton release];

Answer 2

尝试以下代码，

UIButton *btn=[UIButton buttonWithType:UIButtonTypeCustom];
[btn addTarget:self action:@selector(yourfunctionToCall:) forControlEvents:UIControlEventTouchUpInside];
btn.frame=CGRectMake(3, 2, 53, 30);
UIBarButtonItem *btnBack=[[UIBarButtonItem alloc] initWithCustomView:btn];
self.navigationItem.leftBarButtonItem=btnBack;
[btnBack release];
[btn release];

以相同的方式创建 rightBarButtonItem

Answer 3

 self.title = @"Add Item";
   UIBarButtonItem *cancelbutton   = [[[UIBarButtonItem alloc] 
     initWithBarButtonSystemItem:UIBarButtonSystemItemCancel 
     target:self action:@selector(cancel_Clicked:)] autorelease];
self.navigationItem.leftBarButtonItem=cancelbutton;
[cancelbutton release];

     UIBarButtonItem *savebutton = [[[UIBarButtonItem alloc] 
     initWithBarButtonSystemItem:UIBarButtonSystemItemSave 
     target:self action:@selector(save_Clicked:)] autorelease];
self.navigationItem.rightBarButtonItem=savebutton;
[savebutton release];