1.創(chuàng)建UITabBarController

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    // Override point for customization after application launch.
    UIViewController *firstViewController = [[FirstViewController alloc] initWithNibName:@"FirstViewController" bundle:nil];
    UIViewController *secondViewController = [[SecondViewController alloc] initWithNibName:@"SecondViewController" bundle:nil];
    self.tabBarController = [[UITabBarController alloc] init];
    self.tabBarController.viewControllers = @[firstViewController, secondViewController];
    self.tabBarController.delegate = self;  // 設(shè)置代理
    self.window.rootViewController = self.tabBarController;
    [self.window makeKeyAndVisible];
    return YES;
}

2.設(shè)置代理

- (BOOL)tabBarController:(UITabBarController *)tabBarController shouldSelectViewController:(UIViewController *)viewController
{
    NSUInteger shouldSelectIndex = [tabBarController.viewControllers indexOfObject:viewController];
    if (tabBarController.selectedIndex == shouldSelectIndex) {
        return YES;
    }

    CATransition *animation = [CATransition animation];
    animation.duration = 0.75;
    animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
    animation.type = kCATransitionPush;
    if (tabBarController.selectedIndex > shouldSelectIndex) {
        animation.subtype = kCATransitionFromLeft;
    } else {
        animation.subtype = kCATransitionFromRight;
    }
    // 與百度上一般文章不一樣
    [[[tabBarController valueForKey:@"_viewControllerTransitionView"] layer] addAnimation:animation forKey:@"animation"];

    return YES;
}

3.區(qū)別

在百度的文章里，最后一句設(shè)置動(dòng)畫的語(yǔ)句為：

[tabBarController.view.layer addAnimation:animation forKey:@"reveal"];  

這樣會(huì)導(dǎo)致tabBarController的整個(gè)標(biāo)簽欄也跟著一起有動(dòng)畫的效果，這樣的效果并不是很好。

當(dāng)然動(dòng)畫的效果可以自己重新改寫，記下以防自己忘記。