很多App啟動頁過後展示的就是選項卡也就是UITabBarController，這裡講的是最簡單的選項卡的實現，直接繼承自UITabBarController。

Objective-C程式碼：

#import "MainTabBarViewController.h"
#import "HomeViewController.h"
#import "UserCenterViewController.h"

@interface MainTabBarViewController ()

@end

@implementation MainTabBarViewController

- (void
 
)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    self.view.backgroundColor = [UIColor whiteColor];
    [self setupControllers];
    [self setupItems];
}

-(void)setupControllers{
    UINavigationController * nc1 = [[UINavigationController alloc] initWithRootViewController:[[HomeViewController alloc] init]];
    UINavigationController
 
 * nc2 = [[UINavigationController alloc] initWithRootViewController:[[UserCenterViewController alloc] init]];
    self.viewControllers = @[nc1,nc2];
}

-(void)setupItems{
    NSArray *titleArray = @[@"首頁",@"個人中心"];

    NSArray *selectImageName [email protected][@"tabbar_home_selected",@"tabbar_mine_selected"
 
];

    NSArray *unselectImageName [email protected][@"tabbar_home",@"tabbar_mine"];

    for (int i =0; i < titleArray.count; i++) {

        //需要對圖片進行單獨處理,防止在bar上顯示為陰影而不是圖片

        UIImage *selectImage = [UIImage imageNamed:selectImageName[i]];

        selectImage = [selectImage imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];

        UIImage *unselectImage = [UIImage imageNamed:unselectImageName[i]];

        unselectImage = [unselectImage imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];

        UITabBarItem *item = self.tabBar.items[i];

        item.selectedImage = selectImage;

        item.image = unselectImage;

        item.title = titleArray[i];

    }

    //設定tabbar背景圖
    //[self.tabBar setBackgroundImage:[UIImage imageNamed:@"img_tabBar_bg_iOS8.png"]];

    //設定tabbar按鈕被選中時字型的顏色
    [[UITabBarItem appearance] setTitleTextAttributes:@{NSForegroundColorAttributeName : [UIColor redColor]}forState:UIControlStateSelected];
    //設定tabbar按鈕未被選中時字型的顏色
    [[UITabBarItem appearance] setTitleTextAttributes:@{NSForegroundColorAttributeName : [UIColor darkGrayColor]}forState:UIControlStateNormal];
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

/*
#pragma mark - Navigation

// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    // Get the new view controller using [segue destinationViewController].
    // Pass the selected object to the new view controller.
}
*/

@end

其中MainTabBarViewController繼承自UITabBarController，如果專案啟動後就顯示，在Appdelegate中實現如下程式碼即可：

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    // Override point for customization after application launch.
    self.window.rootViewController = [[MainTabBarViewController alloc] init];
    return YES;
}

Swift程式碼：

import UIKit

class MainTabbarViewController: UITabBarController {

    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
        self.view.backgroundColor = UIColor.white
        self.setupControllees()
        self.setupItems()
    }

    func setupControllees() {
        let nc1 = UINavigationController.init(rootViewController: HomeViewController())
        let nc2 = UINavigationController.init(rootViewController: UserCenterViewController())
        self.viewControllers = [nc1,nc2]

    }

    func setupItems() {
        let titleArray = ["首頁","個人中心"]
        let selectImageName = ["tabbar_home_selected","tabbar_mine_selected"]
        let unselectImageName = ["tabbar_home","tabbar_mine"]
        for index in 0...titleArray.count-1 {
            //需要對圖片進行單獨處理,防止在bar上顯示為陰影而不是圖片
            var selectImage = UIImage.init(named: selectImageName[index])
            selectImage = selectImage?.withRenderingMode(UIImageRenderingMode.alwaysOriginal)
            var unselectImage = UIImage.init(named: unselectImageName[index])
            unselectImage = unselectImage?.withRenderingMode(UIImageRenderingMode.alwaysOriginal)
            //初始化items
            let item = self.tabBar.items![index]
            item.selectedImage = selectImage
            item.image = unselectImage
            item.title = titleArray[index]
        }

        //設定tabbar背景圖
        //self.tabBar.backgroundImage = UIImage.init(named: "")
        //設定tabbar按鈕被選中時字型的顏色
        UITabBarItem.appearance().setTitleTextAttributes([NSAttributedStringKey.foregroundColor:UIColor.red], for: UIControlState.selected)
        //設定tabbar按鈕未被選中時字型的顏色
        UITabBarItem.appearance().setTitleTextAttributes([NSAttributedStringKey.foregroundColor:UIColor.darkGray], for: UIControlState.normal)
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }


    /*
    // MARK: - Navigation

    // In a storyboard-based application, you will often want to do a little preparation before navigation
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        // Get the new view controller using segue.destinationViewController.
        // Pass the selected object to the new view controller.
    }
    */

}

其中MainTabBarViewController繼承自UITabBarController，如果專案啟動後就顯示，在Appdelegate中實現如下程式碼即可：

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
        // Override point for customization after application launch.
        self.window?.rootViewController = MainTabbarViewController()
        return true
    }

效果圖：