ios UITabBarController 切换动画

if (itemIndex == 0) {  
    CATransition* animation = [CATransition animation];  
    [animation setDuration:0.2f];  
    [animation setType:kCATransitionMoveIn];  
    [animation setSubtype:kCATransitionFromRight];  
    [animation setTimingFunction:[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut]];  
    [[self.view layer]addAnimation:animation forKey:@"switchView"];  
}  

[super setSelectedIndex:itemIndex];  

blog：http://blog.youkuaiyun.com/linzhiji/article/details/7390664