ios - 在 Interface Builder 中设置 UIToolbar 的位置

Question

当我的应用程序加载时，我无法让 UIToolbar 出现在屏幕底部。无论我如何放置 UIToolbar，也不管我对栏施加的约束，它总是出现在屏幕中间。我的导航栏位置正确，而且我以前在 IB 中定位 UI 元素时从未遇到过问题(尽管我是 iOS 编程的新手)。关于如何确保工具栏保持原位的任何想法？谢谢。

Answer 1

您可能没有正确使用 UINavigationController 玩游戏。见:

https://developer.apple.com/library/ios/documentation/UIKit/Reference/UINavigationController_Class/

Displaying a Navigation Toolbar

A navigation controller object manages an optional toolbar in its view hierarchy. When displayed, this toolbar obtains its current set of items from the toolbarItems property of the active view controller. When the active view controller changes, the navigation controller updates the toolbar items to match the new view controller, animating the new items into position when appropriate.

The navigation toolbar is hidden by default but you can show it for your navigation interface by calling the setToolbarHidden:animated: method of your navigation controller object. If not all of your view controllers support toolbar items, your delegate object can call this method to toggle the visibility of the toolbar during subsequent push and pop operations. To use a custom UIToolbar subclass, use the initWithNavigationBarClass:toolbarClass: method to initialize the navigation controller.

编辑以在评论中包含对问题的回答:

无需编写代码即可完成所有这些工作。您可以在导航 VC 的属性检查器中设置“显示工具栏”。然后，您可以将单个 UIBarButtonItem 拖到特定的 VC 上(工具栏会突然出现在该 VC 上)，并用它们执行通常的导出和操作。