iphone - 如何实现正确的 uinavigationbar 后退按钮功能

Question

当我单击搜索显示控制器的取消按钮时，我想返回上一个视图控制器，我使用了以下代码：

[self.navigationController popToViewController: [self.navigationController.viewControllers objectAtIndex:0] animated:YES];

但它给了我以下错误：

*由于未捕获的异常“NSInternalInconsistencyException”而终止应用程序，原因：“搜索内容导航控制器不得在 -setActive:YES 和 -setActive:NO 之间更改”

Answer 1

[self.navigationController popViewControllerAnimated:YES];

将带您回到堆叠在此导航控制器中的上一个视图控制器。那应该这样做..

Answer 2

I had the same problem and found a solution.

The trick is not to give searchDisplayController to call -setActive:animated: anywhere but in -viewWillDisappear. So you should make your view controller a delegate of the searchBar (to catch taps on "cancel" button) and lay a hidden button on background when searchDisplayController did become active (to catch taps on empty screen space).

In your view controller implement these methods:

- (void)viewWillDisappear:(BOOL)animated
{
    [super viewWillDisappear:animated];
    [self.searchDisplayController setActive:NO animated:animated];
}

- (void)searchBarCancelButtonClicked:(UISearchBar *)searchBar
{
    [self.navigationController popViewControllerAnimated:YES];
}

- (void)backgroundClicked:(id)sender
{
    [self.navigationController popViewControllerAnimated:YES];  
}


- (void)searchDisplayControllerDidBeginSearch:(UISearchDisplayController *)controller
{
    UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
    [button addTarget:self action:@selector(backgroundClicked:) forControlEvents:UIControlEventTouchUpInside];

    CGFloat searchBarHeight = controller.searchBar.frame.size.height;
    button.frame = CGRectOffset(self.view.bounds, 0.f, searchBarHeight) ;
    [self.view addSubview:button];
}

Answer 3

我的问题是 uinavigator 无法设置 searchdisplay 控制器，所以我通过添加以下代码来解决我的问题：

[self.searchDisplayController setActive:NO];

[self.navigationController popViewControllerAnimated:YES];

错误是：

* 断言失败 -[UISearchDisplayController setActive:animated:], /SourceCache/UIKit_Sim/UIKit-1914.84/UISearchDisplayController.m:617 2012-05-13 19:07:44.696 MyApp[3648:11903] *由于未捕获的异常而终止应用程序'NSInternalInconsistencyException'，原因：'搜索内容导航控制器不得在 -setActive:YES 和 -setActive:NO 之间更改'

Answer 4

如果您只需返回上一个视图，则不需要 popToViewController，只需在导航控制器上添加一个后退按钮，您可以单击它返回：-

UIBarButtonItem *backButton = [[UIBarButtonItem alloc] initWithTitle:@"Back"
      style:UIBarButtonItemStylePlain target:nil action:nil];
self.navigationItem.backBarButtonItem = backButton;
[backButton release]; 

或者，如果您真的想弹出视图，请使用：-

UINavigationController *navController = self.navigationController;      

    [UIView beginAnimations:nil context:NULL]; 
[UIView setAnimationDuration: 0.7];
    [UIView setAnimationTransition:<#UIViewAnimationTransitionCurlDown#> forView:navController.view cache:NO];

    [navController popViewControllerAnimated:NO];

    [UIView commitAnimations];

Answer 5

索引 0 处的对象是根视图控制器。所以它是堆栈中的第一个对象。但你只能弹出最后一个对象。而不是使用

[self.navigationController popToViewController: [self.navigationController.viewControllers objectAtIndex:0] animated:YES];

利用

[self.navigationController popToViewController: [self.navigationController.viewControllers lastObject] animated:YES];

或者

[self.navigationController popToViewControllerAnimated:YES];