捕获后退单击导航控制器

Question

在导航控制器应用程序中，假设您已为根控制器分配了标题，推送的视图将在其导航栏的左上角有一个带有该标题的后退按钮。这是自动的。如何根据该后退按钮的click事件执行代码？

Answer 1

实施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： 一个简单的两级层次结构的例子，但可以很容易地更新到更多）

让您的根视图控制器成为UINavigationController委托（例如在viewDidLoad中），然后按如下方式实施：

- (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;
}