在UiTabBarViewController中实现shouldSelectViewController方法

Question

I'm using a storyboard and have UITabBarViewController as my navigation controller. What I need is to use shouldSelectViewController method which is a part of a delegate UITabBarControllerDelegate.

I'm not sure how to override this method in my CustomUiTabBarController .

I was trying to define interface like this:

@interface CustomTabBarController : UITabBarController <UITabBarControllerDelegate>

Then I implemented this:

-(BOOL)tabBarController:(UITabBarController *)tabBarController shouldSelectViewController:(UIViewController *)viewController {
//nothing yet
}

However shouldSelectViewController is not executed when I click on tabs. I also can't set CustomTabBarController class as a delegate of a TabBar in my storyboard because it causes exception.

I clearly leak some iOS undesrtanding here. Please assist.

Answer 1

First of all , get the UITabbarController's object from the application's view controller flow. Then make a tabbarcontroller's property in appDelegate and assign it's value like,

if([viewController isKindOfClass:[UITabBarController class]]){
            UITabBarController *objTabbarController = (UITabBarController *) viewController;
            self.objTabbarController = objTabbarController;
            self.objTabbarController.delegate = self;
        }

assign the delegate to it ,

@interface AppDelegate : UIResponder <UIApplicationDelegate,UITabBarDelegate>

And implement the method in AppDelegate.m file

In shouldSelectViewController just return YES;

And In

 - (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController
{
    NSLog(@"tab selected index %d",tabBarController.selectedIndex);
}