iOS基础之UITabBarController(标签视图控制器)

　　UITabBarController是可以帮我们添加、管理许多的标签项，使我们的程序包含不同的操作模式，由于管理UITabBar可能比较麻烦，系统帮我们对其进行了封装，产生了简单好用的UITabBarController--标签视图控制器。

　　代码演示：

#import "AppDelegate.h"
#import "FirstViewController.h"
#import "SecondViewController.h"
#import "ThirdViewController.h"
#import "FourthViewController.h"
@interface AppDelegate ()

@end

@implementation AppDelegate
-(void)dealloc{
    [_window release];
    [super dealloc];
}
- (void)change{
    [[UITabBar appearance]setTintColor:[UIColor greenColor]];
}
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]]autorelease];
    // Override point for customization after application launch.
    self.window.backgroundColor = [UIColor whiteColor];

    FirstViewController *firstVC = [[FirstViewController alloc]init];
    firstVC.tabBarItem.title = @"帅哥";//设置显示的文本
//    firstVC.tabBarItem.badgeValue = @"爱好";//设置显示角标
    [firstVC.button addTarget:self action:@selector(change) forControlEvents:UIControlEventTouchUpInside];
    firstVC.tabBarItem.image = [[UIImage imageNamed:@"iconfont-cool"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];  //设置图标

    /*
     第一个参数为标签显示的文本
     第二个参数正常状态下显示的图片
     第三个参数选中状态下显示的图片
     注意，图片想要正常显示，必须是png类型
     */

    SecondViewController *secondVC = [[SecondViewController alloc]init];
    UITabBarItem *item = [[UITabBarItem alloc]initWithTitle:@"何二" image:[UIImage imageNamed:@"iconfont-douyixia"] selectedImage:[UIImage imageNamed:@"iconfont-xu"]];
//    创建好标签之后指定为某一个视图控制器的标签
    secondVC.tabBarItem = item;
    [item release];

    //系统自带图标
    ThirdViewController *thirdVC = [[ThirdViewController alloc]init];
    UITabBarItem *systemItem = [[UITabBarItem alloc]initWithTabBarSystemItem:UITabBarSystemItemMostViewed tag:101];
    thirdVC.tabBarItem = systemItem;
    [systemItem release];

    /*
     第一个参数显示文本
     第二个参数正常状态下显示的图片
     第三个参数标记值
     */

    FourthViewController *fourthVC = [[FourthViewController alloc]init];
    UITabBarItem *commomItem = [[UITabBarItem alloc]initWithTitle:@"洪荒" image:[UIImage imageNamed:@"iconfont-zhu"] tag:102];
    fourthVC.tabBarItem = commomItem;

    //一键换肤
    [[UITabBar appearance]setTintColor:[UIColor redColor]];

    UINavigationController *naVC = [[UINavigationController alloc]initWithRootViewController:firstVC];

    //创建标签视图控制器
    UITabBarController *tabbarController = [[UITabBarController alloc]init];
    //设置标签视图控制器需要管理的子视图控制器
    tabbarController.viewControllers = @[naVC,secondVC,thirdVC,fourthVC];
//    tabbarController.selectedIndex = 1;

    //指定window的根视图控制器为标签视图控制器
    self.window.rootViewController = tabbarController;
    [firstVC release];
    [secondVC release];
    [thirdVC release];
    [fourthVC release];
    [naVC release];
    [tabbarController release];

　　总之它可以用标签管理多个页面，非常的方便，很多软件都用到它。