how to run code in tabbarcontroller - objective-c

Question

Im trying to change the icon tint of my unselected tab bar icon images. I have used the patch code below, however, the post that i found this patch code in says to run this in the tab bar controller but i did not know how to do that so i ran it in the -(void)viewDidLoad method in the viewcontroller .m file. It came up with an error saying "Property 'tabBar' not found on object of type 'ViewController *'" How do i fix this?
// set color of selected icons and text to red
self.tabBar.tintColor = [UIColor redColor];
[[UITabBarItem appearance] setTitleTextAttributes:[NSDictionary dictionaryWithObjectsAndKeys: [UIColor redColor], NSForegroundColorAttributeName, nil] forState:UIControlStateSelected];
// set color of unselected text to green
[[UITabBarItem appearance] setTitleTextAttributes:[NSDictionary dictionaryWithObjectsAndKeys:[UIColor greenColor], NSForegroundColorAttributeName, nil]
forState:UIControlStateNormal];
// set selected and unselected icons
UITabBarItem *item0 = [self.tabBar.items objectAtIndex:0];
// this way, the icon gets rendered as it is (thus, it needs to be green in this example)
item0.image = [[UIImage imageNamed:#"unselected-icon.png"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
// this icon is used for selected tab and it will get tinted as defined in self.tabBar.tintColor
item0.selectedImage = [UIImage imageNamed:#"selected-icon.png"];

Answer 1

Instead of using that patch of code, try to do the below in your VC:
[self.tabBarItem setFinishedSelectedImage:[UIImage imageNamed:#"item_seleted.png"] withFinishedUnselectedImage:[UIImage imageNamed:#"item_unselected.png"]];
Edit:
The code above is used when subclassing UITabBarController, so if you insis you need to subclass the 'UITabBarController', change the class of your tabBarController in the storyboard and put that block of code in its viewDidLoad.

Answer 2

You can delete your UIViewController from storyboard and add there UITabBarController and set it as Initial View Controller.
Then you can access this UITabBarController in AppDelegate.m like this:
UITabBarController *tabBarController = (UITabBarController *)self.window.rootViewController;
This is the fast way.
Also you can subclass UITabBarController, set this class in the storyboard and put all your code inside this subclass. (as null has said 15 minutes before :)