1.创建UITabBarController
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
//设置UITabBarController为根视图控制器
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
UIViewController *VcA = [[ViewControllerA alloc] initWithNibName:@"VcA" bundle:nil];
UIViewController *VcB = [[ViewControllerB alloc] initWithNibName:@"VcB" bundle:nil];
self.tabBarController = [[UITabBarController alloc] init];
self.tabBarController.viewControllers = @[VcA, VcB];
self.tabBarController.delegate = self; // 设置代理
self.window.rootViewController = self.tabBarController;
[self.window makeKeyAndVisible];
return YES;
}
2.在UITabBarController设置代理<UITabBarControllerDelegate>
- (BOOL)tabBarController:(UITabBarController *)tabBarController shouldSelectViewController:(UIViewController *)viewController
{
//获取选中的VC
NSUInteger shouldSelectIndex = [tabBarController.viewControllers indexOfObject:viewController];
if (tabBarController.selectedIndex == shouldSelectIndex) {
return YES;
}
CATransition *animation = [CATransition animation];
animation.duration = 0.5;
animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
animation.type = kCATransitionPush;//设置动画类型（可以试着换下看效果）
//判断要选中的VC在已选中的左边还是右边，进行选择或左或右的push效果
if (tabBarController.selectedIndex > shouldSelectIndex) {
animation.subtype = kCATransitionFromLeft;
} else {
animation.subtype = kCATransitionFromRight;
}
// 下面这句可以换成[tabBarController.view.layer addAnimation:animation forKey:@"reveal"]; 但是会导致tabBarController的整个标签栏也跟着一起有动画的效果，这样的效果并不是很好。
[[[tabBarController valueForKey:@"_viewControllerTransitionView"] layer] addAnimation:animation forKey:@"animation"];
return YES;
}
