在iphone sdk上將UIBarButtonItem添加到UINavigationController

Question

我想在UINavigationController上添加后退按鈕，我正在嘗試下面的代碼：

EGOPhotoViewController *photoController = [[EGOPhotoViewController alloc] initWithPhotoSource:source];
    UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:photoController];
    navController.modalTransitionStyle = UIModalTransitionStyleCrossDissolve;
    navController.modalPresentationStyle = UIModalPresentationFullScreen;
   // UINavigationBar *my_bar;
    //UINavigationItem *my_item=[[UINavigationItem alloc] initWithTitle:@"test"];
    UIBarButtonItem* button = [[UIBarButtonItem alloc] initWithTitle: @"Back"
                                                               style: UIBarButtonItemStyleBordered
                                                              target: navController
                                                              action: @selector(onBack)];
    //my_item.rightBarButtonItem = button;
    [[navController navigationItem] setRightBarButtonItem:button];
    self.title=@"Gallery";
    [self presentModalViewController:navController animated:YES];

此代碼輸出如下：

代碼不會在UINavigationController中添加Back Button.I我在UINavigationController上添加了Code to Back按鈕，我的代碼錯誤了什么......！

請任何人幫助我......！

謝謝..！

Answer 1

嘗試從rootviewcontroller類（photoController）viewDidLoad方法添加UIBarButtonItem。

self.navigationItem.rightBarButtonItem =  [[UIBarButtonItem alloc] initWithTitle: @"Back"
                                                           style: UIBarButtonItemStyleBordered
                                                          target: navController
                                                          action: @selector(onBack)];