选项卡(Tab Bar)和导航栏(Navigation Bar)

//AppDelegate.h文件

#import <UIKit/UIKit.h>

@interface AppDelegate : UIResponder <UIApplicationDelegate>

@property (strong, nonatomic) UIWindow *window;

@property(strong,nonatomic) UITabBarController *tabBarController;//底部选项卡控制器

@end

//AppDelegate.m文件

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

    self.window=[[UIWindow alloc]initWithFrame:[[UIScreen mainScreen] bounds]];

    //消息控制器

    MessageViewController *msgController=[[MessageViewController alloc] init];

    UINavigationController *navMsg=[[UINavigationController alloc] initWithRootViewController:msgController];

    //选项卡的图片样式以这种方式处理，避免图片无法完全显示

    UITabBarItem *msgTabItem = [[UITabBarItem alloc]initWithTitle:@"消息" image:[[UIImage imageNamed:@"tab_message@3x.png"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal] selectedImage:[[UIImage imageNamed:@"tab_message_select@3x.png"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal]];

    navMsg.tabBarItem=msgTabItem;

    //联系人控制器

    ContactViewController *conController=[[ContactViewController alloc] init];

    UINavigationController *navCon=[[UINavigationController alloc] initWithRootViewController:conController];

    UITabBarItem *conTabItem = [[UITabBarItem alloc]initWithTitle:@"联系人" image:[[UIImage imageNamed:@"tab_ contact@3x.png"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal] selectedImage:[[UIImage imageNamed:@"tab_ contact_select@3x.png"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal]];

    navCon.tabBarItem=conTabItem;

    //动态控制器

    DynamicViewController *dynController=[[DynamicViewController alloc] init];

    UINavigationController *navDyn=[[UINavigationController alloc] initWithRootViewController:dynController];

    UITabBarItem *dynTabItem = [[UITabBarItem alloc]initWithTitle:@"动态" image:[[UIImage imageNamed:@"tab_ dynamic@3x.png"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal] selectedImage:[[UIImage imageNamed:@"tab_ dynamic_select@3x.png"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal]];

    navDyn.tabBarItem=dynTabItem;

    self.tabBarController=[[UITabBarController alloc] init];

    self.tabBarController.viewControllers=@[navMsg,navCon,navDyn];

    self.tabBarController.selectedIndex=0;

    //由于iPhone是单窗口程序，所以也就只有这么一个Window对象，而且是UIWindow，不是NSWindow。而根据文档上所说：这个是便捷方法，去使被使用对象的主窗口显示到屏幕的最前端。

    [self.window makeKeyAndVisible];

    return YES; 

}