1

我想知道如何识别标签栏中的项目？

我有一个包含 NAvigationController 的 tabBarController，如下所示：

NSMutableArray *localViewControllersArray = [[NSMutableArray alloc] initWithCapacity:6];

每个 navigationController 都在这个数组中。

我使用以下方法管理每个选项卡栏项中的操作：

- tabBarController:(UITabBarController*)tabBarController didSelectViewController:(UIViewController*)viewController

我在这种方法中，即：

if (viewController == [self.tabBarController.viewControllers objectAtIndex:0])

像这样我识别我点击的标签栏项目。

但问题是您可以在 iphone 屏幕中编辑 Tabbar（因为数组中有 6 个视图控制器初始化标签栏）然后，我使用的方式不正确，因为我可以更改视图控制器的位置当我使用这个编辑工具时在标签栏中。

谢谢

4

3 回答 3

6

您可以使用UITabBarItem's tag 属性给每个UITabBarItem唯一的数字标识符，然后进行比较。

例子：

#define FirstViewController 1
#define SecondViewController 2
switch ([[viewController tabBarItem] tag]) {
  case FirstViewController:
    //the user selected your first view controller, no matter where it is on the tabbar
    break;
  case SecondViewController:
    break;
  ... etc
}

您可以记住指向每个的指针navigationControllers并将它们与viewController参数进行比较。

例子：

//during your initial setup of the tabBarController:
UIViewController * firstViewController = //The view controller in the first tab
UIViewController * secondViewController = //The view controller in the second tab

...

if (viewController == firstViewController) {
  ...
} else if (viewController == secondViewController) {
  ...
}

您可以禁止在您的UITabBarController（传递一个空数组或nil控制器的customizableViewControllers属性）上进行编辑。

例子：

[myTabBarController setCustomizableViewControllers:nil];
于 2009-08-15T14:27:01.583 回答
0

但是，我正在创建这样的 ViewController：（然后我不能制作#define，或者输入不同的名称）

(UINavigationController *)createNavigationControllerWrappingViewControllerForDataSourceOfClass:(Class)datasourceClass {

id<VideosDataSource,UITableViewDataSource> dataSource = [[datasourceClass alloc] init];

// create the VideosTableViewController and set the datasource
VideosTableViewController *theViewController;   
theViewController = [[VideosTableViewController alloc] initWithDataSource:dataSource];

// create the navigation controller with the view controller
UINavigationController *theNavigationController;
theNavigationController = [[UINavigationController alloc] initWithRootViewController:theViewController];

// before we return we can release the dataSource (it is now managed by the ElementsTableViewController instance
[dataSource release];

// and we can release the viewController because it is managed by the navigation controller
[theViewController release];

return theNavigationController;

}

(void)setupPortraitUserInterface {

// a local navigation variable
// this is reused several times
UINavigationController *localNavigationController;

// Create a tabbar controller and an array to contain the view controllers
tabBarController = [[UITabBarController alloc] init];

// define a custom frame size for the entire tab bar controller that will be in the
// bottom half of the screen.
CGRect tabBarFrame;
tabBarFrame = CGRectMake(0, 0, 320, 460);
tabBarController.view.frame = tabBarFrame;

NSMutableArray *localViewControllersArray = [[NSMutableArray alloc] initWithCapacity:6];

// setup the 6 view controllers for the different data representations

// create the view controller and datasource for the VideosSortedBySuggestionsDataSource
// wrap it in a UINavigationController, and add that navigationController to the 
// viewControllersArray array

localNavigationController = [self createNavigationControllerWrappingViewControllerForDataSourceOfClass:[VideosSortedBySuggestionsDataSource class]];
[localViewControllersArray addObject:localNavigationController];

// the localNavigationController data is now retained by the application delegate
// so we can release the local variable
[localNavigationController release];


// repeat the process for the VideosSortedBySuggSearchDataSource
localNavigationController = [self createNavigationControllerWrappingViewControllerForDataSourceOfClass:[VideosSortedBySuggSearchDataSource class]];
[localViewControllersArray addObject:localNavigationController];

// the localNavigationController data is now retained by the application delegate
// so we can release the local variable
[localNavigationController release];            


// repeat the process for the VideosSortedByMostViewedDataSource
localNavigationController = [self createNavigationControllerWrappingViewControllerForDataSourceOfClass:[VideosSortedByMostViewedDataSource class]];
[localViewControllersArray addObject:localNavigationController];

// the localNavigationController data is now retained by the application delegate
// so we can release the local variable
[localNavigationController release];


// repeat the process for the VideosSortedByTopRatedDataSource
localNavigationController = [self createNavigationControllerWrappingViewControllerForDataSourceOfClass:[VideosSortedByTopRatedDataSource class]];
[localViewControllersArray addObject:localNavigationController];

// the localNavigationController data is now retained by the application delegate
// so we can release the local variable
[localNavigationController release];


// repeat the process for the VideosSortedBySearchDataSource
localNavigationController = [self createNavigationControllerWrappingViewControllerForDataSourceOfClass:[VideosSortedBySearchDataSource class]];
[localViewControllersArray addObject:localNavigationController];

// the localNavigationController data is now retained by the application delegate
// so we can release the local variable
[localNavigationController release];


// repeat the process for the VideosSortedBySearchDataSource
localNavigationController = [self createNavigationControllerWrappingViewControllerForDataSourceOfClass:[VideosSortedBySearchDataSource class]];
[localViewControllersArray addObject:localNavigationController];

// the localNavigationController data is now retained by the application delegate
// so we can release the local variable
[localNavigationController release];


// set the tab bar controller view controller array to the localViewControllersArray
tabBarController.viewControllers = localViewControllersArray;
// the localViewControllersArray data is now retained by the tabBarController
// so we can release this version
[localViewControllersArray release];
// set the window subview as the tab bar controller
[self.view addSubview:tabBarController.view];

}

于 2009-08-15T19:21:02.517 回答
0

为此，我从 Elements 演示开始。在那个演示中，每个数据源都有自己的覆盖名称。然后，任何时候我需要为特定选项卡做某事（因为它的数据源与其他选项卡不同），在我的主导航控制器中，我会：

if (datasource.name == @"Some name") {
    // something
}
于 2009-08-16T21:42:07.053 回答