如何迭代應用程序上的所有UIViewControllers

Question

我有一個這種結構的xib：

- Tab Bar Controller
-- Tab Bar
-- NavigationController
--- Navigation Bar
--- News List View Controller
---- Navigation Item
--- Tab Bar Item

-- NavigationController
--- Navigation Bar
--- News List View Controller
---- Navigation Item
--- Tab Bar Item
-- NavigationController
--- Navigation Bar
--- News List View Controller
---- Navigation Item
--- Tab Bar Item
[...]

如何編寫循環以在每次迭代中獲取每個UIViewController（新聞列表視圖控制器）？

Answer 1

像這樣以代碼方式訪問它們：

NSArray * controllerArray = [[self navigationController] viewControllers];

for (UIViewController *controller in controllerArray){
   //Code here.. e.g. print their titles to see the array setup;
   NSLog(@"%@",controller.title);
}

Answer 2

如果您使用的是iOS 5，可以執行以下操作：

- (void) processViewController: (UIViewController *) viewController {
    //do something with viewcontroller here
    NSLog(@"I'm viewcontroller %@", viewController);
    for ( UIViewController *childVC in viewController.childViewControllers ) {
        [self processViewController:childVC];
    }
}

並開始有趣的：

[self processViewController:myRootViewController]; //would be the tabbarcontroller in your case

編輯：我不確定你想在這里實現什么，但是這段代碼是為了遍歷整個樹。

編輯2：

對於iOS 4，請嘗試以下方法：

- (void) processViewController: (UIViewController *) viewController {
    //do something with viewcontroller here
    NSLog(@"I'm viewcontroller %@", viewController);

    if ( [viewController isKindOfClass:[UITabBarController class]] ) {
        for ( UIViewController *childVC in ((UITabBarController *)viewController).viewControllers ) {
            [self processViewController:childVC];
        }
    }
    else if ( [viewController isKindOfClass:[UINavigationController class]] ) {
        for ( UIViewController *childVC in ((UINavigationController *)viewController).viewControllers ) {
            [self processViewController:childVC];
        }
    }
}

注意：您需要添加任何具有subviewcontrollers的自定義viewcontroller。 如果你有任何..根視圖控制器再次啟動它。