向UITabbarController添加其他UITabbarItem [英] Adding additional UITabbarItem to UITabbarController

问题描述

我想知道是否有办法向现有的 UITabBarController 添加其他 UITabBarItem 。它不需要在运行时。

I am wondering if there is a way to add an additional UITabBarItem to my exisiting UITabBarController. It doesn't need to be in runtime.

我要做的就是单击此按钮时要 presentModalViewController：在我实际可见的ViewController上，它应该是TabBarController或其控制器。

All I want to do is when hitting this button I want to presentModalViewController: over my actually visible ViewController, which should either be the TabBarController or its controllers.

希望这很清楚，如果不能的话，请随时提问。

Hopefully this is clear enough, if not, feel free to ask.

推荐答案

根据我的研究，您无法将UITabBarItem添加到由UITabBarController管理的UITabBar。

As a result of my research you cannot add a UITabBarItem to a UITabBar that is managed by a UITabBarController.

由于您可能是通过添加视图控制器列表来添加UITabBarItem的，因此这也是您选择添加其他自定义UITabBarItems的方式，我现在将显示：

Since you maybe have added your UITabBarItem by adding a list of view controller, this is also the way of your choice to add further custom UITabBarItems, as i will show now:

前提条件：
如前所述，您可能已经通过添加视图控制器列表来添加了UITabBarItems：

Pre-Conditions: As i mentioned before, you maybe have added your UITabBarItems by adding a list of view controller:

tabbarController = [[UITabBarController alloc] init]; // tabbarController has to be defined in your header file

FirstViewController *vc1 = [[FirstViewController alloc] initWithNibName:@"FirstViewController" bundle:[NSBundle mainBundle]];
vc1.tabBarItem.title = @"First View Controller"; // Let the controller manage the UITabBarItem

SecondViewController *vc2 = [[SecondViewController alloc] initWithNibName:@"SecondViewController" bundle:[NSBundle mainBundle]];
vc2.tabBarItem.title = @"Second View Controller";

[tabbarController setViewControllers:[NSArray arrayWithObjects: vc1, vc2, nil]];

tabbarController.delegate = self; // do not forget to delegate events to our appdelegate

添加自定义UITabBarItems：
现在，既然您知道如何通过添加视图控制器来添加UITabBarItems，则还可以使用相同的方法来添加自定义UITabBarItems：

Adding custom UITabBarItems: Now since you know how to add UITabBarItems through adding view controller, you can also use the same way to add custom UITabBarItems:

UIViewController *tmpController = [[UIViewController alloc] init];
tmpController.tabBarItem.title = @"Custom TabBar Item";
// You could also add your custom image:
// tmpController.tabBarItem.image = [UIImage alloc]; 
// Define a custom tag (integers or enums only), so you can identify when it gets tapped:
tmpController.tabBarItem.tag = 1;

修改以上行：

[tabbarController setViewControllers:[NSArray arrayWithObjects: vc1, vc2, tmpController, nil]];

[tmpController release]; // do not forget to release the tmpController after adding to the list

之后释放tmpController很好，现在您有了

All fine, now you have your custom button in your TabBar.

如何处理此自定义UITabBarItem的事件？

很简单，看一下：

将UITabBarControllerDelegate添加到您的AppDelegate类（或持有tabbarController的类）中。

Add the UITabBarControllerDelegate to your AppDelegate class (or the class which is holding the tabbarController).

@interface YourAppDelegate : NSObject <UIApplicationDelegate, UITabBarControllerDelegate> { }

通过添加以下功能来满足协议定义：

Fit the protocol definition by adding this function:

- (void)tabBarController:(UITabBarController *)theTabBarController didSelectViewController:(UIViewController *)viewController {
  NSUInteger indexOfTab = [theTabBarController.viewControllers indexOfObject:viewController];

  UITabBarItem *item = [theTabBarController.tabBar.items objectAtIndex:indexOfTab];
  NSLog(@"Tab index = %u (%u), itemtag: %d", indexOfTab, item.tag);  
  switch (item.tag) {
    case 1:
      // Do your stuff
      break;

    default:
      break;
  }
} 

现在，您拥有创建和处理自定义内容所需的一切UITabBarItems。
希望这会有所帮助。
玩得开心....

Now you have all you need to create and handle custom UITabBarItems. Hope this helps. Have fun....

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