在導航控制器中捕獲點擊

Question

在導航控制器應用程序中，假設您已經爲根控制器分配了標題，則推送的視圖將在導航欄的左上角有一個帶有該標題的後退按鈕。這是自動的。我如何根據後退按鈕的點擊事件來執行代碼？

Answer 1

實施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 

編輯： 例如，對於一個簡單的兩個層次結構，但可以很容易地更新，以更）

讓你的根視圖控制器UINavigationController委託（例如，在viewDidLoad）和然後執行如下：

- (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; 
}