iphone - 捕获导航 Controller 中的后退单击

Question

在导航 Controller 应用程序中，假设您已为根 Controller 分配了一个标题，则推送的 View 将有一个后退按钮，该标题位于其导航栏的左上角。那是自动的。如何根据后退按钮的单击事件执行代码？

Answer 1

实现 UINavigationControllerDelegate

@protocol UINavigationControllerDelegate <NSObject>

@optional

// Called when the navigation controller shows a new top view controller via a push, pop or setting of the view controller stack.
- (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated;
- (void)navigationController:(UINavigationController *)navigationController didShowViewController:(UIViewController *)viewController animated:(BOOL)animated;

@end

编辑: 简单的两级层次结构的示例，但可以轻松更新为更多)

使您的 Root View Controller 成为 UINavigationController 委托(delegate)(例如在 viewDidLoad 中)，然后按如下方式实现:

- (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated
{
    if (viewController == self )
    {
        if (lastView == theOtherView)
        {
            // Pop from other view to root view
        }
    }
    else if (viewController == theOtherView)
    {
        // push to other view
    }
    lastView = viewController;
}