六，UITabBarController

简介

跟UINavigationController类似，UITabBarController也可以轻松地管理多个控制器，轻松完成控制器之间的切换，典型例子就是QQ、微信等应用.

属性

• UITabBarItem
  UITabBar上面显示的每一个Tab都对应着一个ViewController，我们可以通过设置viewcontroller.tabBarItem属性来改变tabbar上对应的tab显示内容。否则系统将会根据viewController的title自动创建一个，该tabBarItem只显示文字，没有图像。当我们自己创建UITabBarItem的时候，我们可以显示的指定显示的图像和对应的文字描述。当然还可以通过setFinishedSelectedImage:withFinishedUnselectedImage:方法给选中状态和非选中状态指定不同的图片

UITabBarItem *item = [[UITabBarItem alloc] initWithTitle:@"Second" image:nil tag:2];[item setFinishedSelectedImage:[UIImage imageNamed:@"second.png"]    withFinishedUnselectedImage:[UIImage imageNamed:@"first.png"]];viewController2.tabBarItem = item;

• UITabBar(高度为49)
• 　UITabBar自己有一些方法是可以改变自身状态，但是对于UITabBarController自带的tabBar，我们不能直接去修改其状态。任何直接修改tabBar的操作将会抛出异常；

简单使用1（AppDelegate）

 // 1.创建窗口    self.window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];    // 2.设置窗口的根控制器    UITabBarController *tabBarVc = [[UITabBarController alloc] init];    self.window.rootViewController = tabBarVc;    // 添加子控制器    UIViewController *vc = [[UIViewController alloc] init];    vc.tabBarItem.title = @"消息";    //设值显示的小红点    vc.tabBarItem.badgeValue = @"1000";    vc.tabBarItem.image = [UIImage imageNamed:@"tab_recent_nor"];    // 在iOS7之后,系统默认会把选中的按钮自动渲染.    vc.view.backgroundColor = [UIColor redColor];    [tabBarVc addChildViewController:vc];    // tabBar控制器会把自己的子控制器的view添加到自己身上    // 默认tabBar控制器会把自己的第一个子控制器的view添加的自己身上    UIViewController *vc1 = [[UIViewController alloc] init];    vc1.view.backgroundColor = [UIColor greenColor];    vc1.tabBarItem.title = @"联系人";    [tabBarVc addChildViewController:vc1];    UIViewController *vc2 = [[UIViewController alloc] init];    vc2.view.backgroundColor = [UIColor yellowColor];    [tabBarVc addChildViewController:vc2];    // 3.显示窗口    [self.window makeKeyAndVisible];    return YES;

结合导航控制器

• 创建分栏控制器：

// 创建分栏控制器管理的子视图控制器- (void)createViewControllers{    OneViewController *oneVC = [[OneViewController alloc] init];    MyNavgationController *navCtrl1 = [[MyNavgationController alloc] initWithRootViewController:oneVC];//    navCtrl1.tabBarItem = [[UITabBarItem alloc] initWithTabBarSystemItem:UITabBarSystemItemSearch tag:0];    TwoViewController *twoVC = [[TwoViewController alloc] init];    UINavigationController *navCtrl2 = [[UINavigationController alloc] initWithRootViewController:twoVC];    ThreeViewController *threeVC = [[ThreeViewController alloc] init];    FourViewController *fourVC = [[FourViewController alloc] init];    FiveViewController *fiveVC = [[FiveViewController alloc] init];    SixViewController *sixVC = [[SixViewController alloc] init];    // 分栏控制器管理的视图控制器的tabBarController属性，自动指向分栏控制器。    // 当分栏控制器管理的视图控制器的个数超过五个时，会自动创建一个more的导航控制器，并且自动将第五个以及以后的视图控制器添加到more导航控制器中。    self.viewControllers = @[navCtrl1, navCtrl2, threeVC, fourVC, fiveVC,  sixVC];}

• 在MyNavgationController里面，重写跳转方法 ：

- (void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated{    //1. 取出分栏    UITabBar *tabBar = self.tabBarController.tabBar;    // 将frame左移分栏的宽度    CGRect frame = tabBar.frame;    frame.origin.x -= tabBar.frame.size.width;    // 动画影藏tabBar    [UIView animateWithDuration:0.28 animations:^{        tabBar.frame = frame;    }];    [super pushViewController:viewController animated:animated];}- (UIViewController *)popViewControllerAnimated:(BOOL)animated{    //1. 取出分栏    UITabBar *tabBar = self.tabBarController.tabBar;    // 将frame左移分栏的宽度    CGRect frame = tabBar.frame;    frame.origin.x += tabBar.frame.size.width;    // 动画影藏tabBar    [UIView animateWithDuration:0.28 animations:^{        tabBar.frame = frame;    }];    return [super popViewControllerAnimated:YES];}

在自定义tabbarController

//在继承自UITabBarController-(void)addTabBarSubContrller{    NSMutableArray *mutArray = [[NSMutableArray alloc]init];    //主页    HHHomeViewController *home = [[HHHomeViewController alloc]init];    UINavigationController *navHome = [[UINavigationController alloc]initWithRootViewController:home];    [mutArray addObject:navHome];    //团购优惠也    HHGroupViewController *group = [[HHGroupViewController alloc]init];    UINavigationController *navGroup = [[UINavigationController alloc]initWithRootViewController:group];    [mutArray addObject:navGroup];    //发现    HHFinderViewController *finder = [[HHFinderViewController alloc]init];    UINavigationController *navFinder = [[UINavigationController alloc]initWithRootViewController:finder];    [mutArray addObject:navFinder];    //我的个人中心也    HHMyMessagesViewController *myMessage = [[HHMyMessagesViewController alloc]init];    UINavigationController *navMyMessage = [[UINavigationController alloc]initWithRootViewController:myMessage];    [mutArray addObject:navMyMessage];    //添加到tabbar中    [self setViewControllers:mutArray];}//在子控制器中- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil{    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];    if (self) {        UIImage *norimg = [UIImage imageNamed:@"main_index_home_normal"];        UIImage *selectImg = [UIImage imageNamed:@"main_index_home_pressed"];        norimg = [UIImage scaleImage:norimg toScale:0.4];        selectImg = [UIImage scaleImage:selectImg toScale:0.4];      UITabBarItem *item = [[UITabBarItem alloc]initWithTitle:@"首页" image:norimg selectedImage:selectImg];        self.tabBarItem = item;//        item.imageInsets = UIEdgeInsetsMake(10, 10, 10, 10);    }    return self;}