ios - UITabBarController - 子(选项卡)ViewControllers 的不正确和不一致的边界

Question

我有一个带有两个选项卡的 UITabBarController。每个选项卡都是一个 UITableViewController。

当 UITabBarController 出现时，两个选项卡 View 各自具有不正确的边界。第一个选项卡正确地位于导航栏下方，但延伸到底部的选项卡栏下方。第二个选项卡正好相反，从导航栏下方开始，但正确地停在底部的选项卡栏之前。

我正在创建和呈现 TabBarController，如下所示:

ActiveListTabBarViewController* listTabBarController = [[ActiveListTabBarViewController alloc] initWithListController:_listController];
UINavigationController* nc = [[UINavigationController alloc] initWithRootViewController:listTabBarController];
[self presentViewController:nc animated:YES completion:^(){}];

然后在 TabBarController 的 init 中，创建并添加子(选项卡) View ，如下所示:

_todoListViewController = [[BasicTableViewController alloc] initWithList:[_controller itemsToDo]];
_todoListViewController.delegate = self;
_todoListViewController.title = @"To Do";
_completedListViewController = [[BasicTableViewController alloc] initWithList:[_controller itemsDone]];
_completedListViewController.delegate = self;
_completedListViewController.title = @"Completed";

[self setViewControllers:@[_todoListViewController, _completedListViewController]];

我做错了什么？

谢谢，加文

更新:按照建议将以下方法添加到BasicTableViewController:

- (UIRectEdge)edgesForExtendedLayout
{
    return UIRectEdgeNone;
}

第一个选项卡的行为有所改进并且位置正确，但第二个选项卡保持不变。现在情况如下:

有什么建议吗？干杯。

Answer 1

问题是由我呈现 UITabBarController

的方式引起的

ActiveListTabBarViewController* listTabBarController = [[ActiveListTabBarViewController alloc] initWithListController:_listController];
UINavigationController* nc = [[UINavigationController alloc] initWithRootViewController:listTabBarController];
[self presentViewController:nc animated:YES completion:^(){}];

回到 Apple 的文档，我不确定这是否是呈现 UITabBarController 的有效方式。也就是说，将其呈现为另一个 View Controller 的子级。

不是。以下是一些片段，为我证实了这一点；由此以及由此产生的变化，我假设像上面那样呈现 TabBarController 是不正确的。

来自: https://developer.apple.com/library/ios/documentation/WindowsViews/Conceptual/ViewControllerCatalog/Chapters/TabBarControllers.html

Before creating a tab bar interface, you need to decide how you intend to use a tab bar interface. Because it imposes an overarching organization on your data,you should use one only in these specific ways:

• Install it directly as a window’s root view controller.
• Install it as one of the two view controllers in a split view interface. (iPad only)
• Present it modally from another view controller.
• Display it from a popover. (iPad only)

来自: https://developer.apple.com/library/ios/documentation/uikit/reference/UITabBarController_Class/Reference/Reference.html

Unlike other view controllers, a tab bar interface should never be installed as a child of another view controller.

进一步说明:

A tab bar controller is a container view controller that you use to divide your app into two or more distinct modes of operation.

A navigation controller presents data that is organized hierarchically and is an instance of the UINavigationController class. The methods of this class provide support for managing a stack-based collection of content view controllers.

我将 UITabBarController 呈现为导航 Controller 的 Root View 的原因是我想要导航栏...

这就是我现在在 TabBarController 的 init 中实现它的方式:

- (id)initWithListController:(BasicListController *)controller
{
    self = [super init];
    if (self) {
        _controller = controller;

        _todoListViewController = [[BasicTableViewController alloc] initWithList:[_controller itemsToDo]];
        _todoListViewController.delegate = self;
        _todoListViewController.title = @"To Do";

        _completedListViewController = [[BasicTableViewController alloc] initWithList:[_controller itemsDone]];
        _completedListViewController.delegate = self;
        _completedListViewController.title = @"Completed";

        UINavigationController* ncTodo = [[UINavigationController alloc] initWithRootViewController:_todoListViewController];
        UINavigationController* ncCompleted = [[UINavigationController alloc] initWithRootViewController:_completedListViewController];

        [self setViewControllers:@[ncTodo, ncCompleted]];

        UIBarButtonItem* doneButton = [[UIBarButtonItem alloc] initWithTitle:@"Done" style:UIBarButtonItemStylePlain target:self action:@selector(doneTap:)];
        _todoListViewController.navigationItem.leftBarButtonItem = doneButton;
        _completedListViewController.navigationItem.leftBarButtonItem = doneButton;
    }
    return self;
}

请注意，我无需对以下内容执行任何操作:

• edgesForExtendedLayout
• 自动调整 ScrollViewInsets
• extendedLayoutIncludesOpaqueBars

iOS 7 默认尊重导航栏和标签栏(与上面的原始屏幕截图不同，当 UITabBarController 显示不正确时)。