iOS在UITabBar中更改UITabBarButton的框架

Question

In my app I have a UITabBarController in which I give custom selected/unselected images in my AppDelegate as follows:

UIImage *selectedImage = [UIImage imageNamed:@"home-tab-selected"];
UIImage *unselectedImage = [UIImage imageNamed:@"home-tab"];
UITabBar *tabBar = tabController.tabBar;
UITabBarItem *item1 = [tabBar.items objectAtIndex:0];
[item1 setFinishedSelectedImage:selectedImage withFinishedUnselectedImage:unselectedImage];

The images I have are 100x100, much larger than the normal tab bar items. All works well, and my images are placed nicely and look great.

The issue I am having is that the frame of the underlaying UITabBarButton remains 76x48, leaving only a small portion of my tabs 'touchable'. (Image below with a border around the frame)

To attempt to fix this, in my subcalssed UITabBarController viewDidLoad , I go through each UITabBarButton , and set the frame as follows:

for (UIView* subView in self.tabBar.subviews)
{
    if ([subView isKindOfClass:NSClassFromString(@"UITabBarButton")])
    {

        [subView setFrame:CGRectMake(subView.frame.origin.x, subView.frame.origin.y, 100, 100)];


    }
}

After I do that, I log the frames and they do change-- BUT the frame never changes in my tab bar-- I still only see and can touch in the smaller red box.

Is this because Apple does not allow you to change these frames or am I doing something wrong here?

Any help apperciated! Thanks!

EDIT:

In the end I just ended up making my tab images smaller. I found a height of 70px still picks up most touches.

Answer 1

The layout of your UITabBarController 's view might change after loading: Additional UITabBarItem s could be added, of the user could switch to landscape orientation.

Before iOS 6, there wasn't a way to configure complex layouts. Since UITabBar is a very old class, it's most likely doing its work in the layoutSubviews method.

You could subclass UITabBar and override said method, but if you go that far, you might want to think about creating your own tab bar, which in the end is just a UIView with a few UIButton s.

Answer 2

Had a similiar problem with the underlying UITabBarButtons. I solved it by setting the UITabBar's "Item positioning" attribute to "Fill".