UITabBarController是一個容器控制器，繼承於UIViewController，一般情況下作為window的根檢視控制器

UITabBarController自帶一個UITabBar

首先建立一個UItabBarController

UITabBarController* barTC =[[UITabBarControlleralloc]init];

作為window的根檢視

self.window.rootViewController= barTC;

設定標題為首頁

 barTC.navigationItem.title= @"首頁";

建立5個檢視控制器

FirstViewController * firstVC =[[FirstViewControlleralloc]init];

SecondViewController * secondVC =[[SecondViewControlleralloc]init];

ThirdViewController * thirdVC =[[ThirdViewControlleralloc]init];

FourViewController * fourVC =[[FourViewControlleralloc]init];

FiveViewController* fiveVC  =[[FiveViewController

再給5個檢視新增導航控制器

UINavigationController* navigationVC1 =[[UINavigationControlleralloc]initWithRootViewController:firstVC];

UINavigationController * navigationVC2 =[[UINavigationControlleralloc]initWithRootViewController:secondVC];

UINavigationController* navigationVC3 =[[UINavigationController

 UINavigationController* navigationVC4 =[[UINavigationControlleralloc]initWithRootViewController:fourVC];

 UINavigationController* navigationVC5 =[[UINavigationControlleralloc]initWithRootViewController:fiveVC];

//UITabBarController的子檢視控制器

    barTC.viewControllers=@[navigationVC1,navigationVC2,navigationVC3,navigationVC4,navigationVC5];

  firstVC.view.backgroundColor= [UIColorredColor];

   firstVC.tabBarItem.title= @"首頁";

 //設定角標

   firstVC.tabBarItem.badgeValue= @"33";

 //UItabBar會對圖片進行渲染，如果不想渲染的話就需要使用(UIImageRenderingModeAlwaysOriginal)。

   firstVC.tabBarItem.image= [[UIImageimageNamed:@"home.png"]imageWithRenderingMode:(UIImageRenderingModeAlwaysOriginal)];

   secondVC.view.backgroundColor= [UIColorblackColor];

   secondVC.tabBarItem.title= @"發現";

   secondVC.tabBarItem.image= [[UIImageimageNamed:@"find.png"]imageWithRenderingMode:(UIImageRenderingModeAlwaysOriginal)];

   thirdVC.view.backgroundColor= [UIColorwhiteColor];

   thirdVC.tabBarItem.title= @"設定";

   thirdVC.tabBarItem.image= [[UIImageimageNamed:@"setting.png"]imageWithRenderingMode:(UIImageRenderingModeAlwaysOriginal)];

   fourVC.view.backgroundColor= [UIColorgrayColor];

   fourVC.tabBarItem.title= @"購物";

   fourVC.tabBarItem.image= [[UIImageimageNamed:@"shopping.png"]imageWithRenderingMode:(UIImageRenderingModeAlwaysOriginal)];

   fiveVC.view.backgroundColor= [UIColorgreenColor];

   fiveVC.tabBarItem.title= @"聯絡人";

   fiveVC.tabBarItem.image= [UIImageimageNamed:@"contact.png"];

//

//   firstVC.tabBarItem = [[[UITabBarItemalloc]initWithTabBarSystemItem:(UITabBarSystemItemBookmarks)tag:1]autorelease];

//   firstVC.tabBarItem.badgeValue [email protected]"23";

//   secondVC.tabBarItem  =[[[UITabBarItemalloc]initWithTabBarSystemItem:(UITabBarSystemItemContacts)tag:2]autorelease];

//   thirdVC.tabBarItem = [[[UITabBarItemalloc]initWithTabBarSystemItem:(UITabBarSystemItemDownloads)tag:3]autorelease] ;

//   fourVC.tabBarItem = [[[UITabBarItemalloc]initWithTitle:@"發現" image:[UIImage imageNamed:@"find.png"]selectedImage:[UIImageimageNamed:@"map.png"]]autorelease];

//   fiveVC.tabBarItem = [[[UITabBarItemalloc]initWithTitle:@"首頁" image:[UIImage imageNamed:@"home.png"]selectedImage:[UIImage imageNamed:nil]]autorelease];

//   SixViewController * sixVC = [[SixViewControlleralloc]init];

//   sixVC.tabBarItem = [[[UITabBarItemalloc]initWithTitle:@"猴子" image:[UIImage imageNamed:@"monkey.png"]selectedImage:nil]autorelease];

效果圖如下：

三大檢視控制器組成的框架結構--UItabBarController、UINavigationController、UITableViewController

    第一種--UINavigationController管理UITabBarController,這種結構UINavigationBar上面的內容是不變的。

    第二種結構---UItabBarController管理UINavigationController，這種結構每一個具體的檢視控制器可以設定自己在navigationBar上面的內容

    主要事項：1.如果要給tabBarItem，應該給對應的navigationcontroller設定

    2.如果設定navigationBarItem，應該給具體的檢視控制器設定。一般情況下會在檢視控制器的內部方法裡面設定

UITabBarControllerDelegate協議裡面有如下方法，要定義代理物件為自身   barTC.delegate=self;

- (void)tabBarController:(UITabBarController *)tabBarControllerdidSelectViewController:(UIViewController *)viewController