How to stop loading the view on tabbar item selection? - iphone

Question

I have a tabbar controller with three tabs . In first tab I have a navigation controller . Now User navigates in the first tab to do some payment so I have disabled the default back buttons cause I dont want user to use back button in between transaction. But when user presses the tab again he/she navigates to the root view . How can I detect the tabbar selection or how do I avoid loading the tab again ?
Please help me on this !! Thank You !!
Note: I am not sure if my question has been already answered on stackoverflow in some other post but I did search and did not get any answer . If so , please feel free to redirect me to that answer and delete this post . Thanx !

Answer 1

Check the UITabBarControllerDelegate Protocol Reference.
The basic idea is that the tabBarController:shouldSelectViewController: selector in your UITabBarController delegate is called whenever the user clicks on tab item.
Thus, by appropriately defining that method, you get a chance to do your own processing before the current view controller is replaced by the one the user selected by clicking in the tab bar.
So, simply return NO from this selector in case you wish to prevent the current view controller to be replaced, i.e. when a transaction is ongoing.

Answer 2

In this way you can open any controller or perform any action on the selection of specific index.
func tabBarController(_ tabBarController: UITabBarController, shouldSelect viewController: UIViewController) -> Bool {
let selectedIndex = tabBarController.viewControllers?.firstIndex(of: viewController)!
if selectedIndex == 1{
//Do any thing.
return false
}
return true
}

Answer 3

You have to do it this way..
- (BOOL)tabBarController:(UITabBarController *)tbc shouldSelectViewController:(UIViewController *)vc
{
UIViewController *tbSelectedController = tbc.selectedViewController;
if ([tbSelectedController isEqual:vc])
{
return NO;
}
return YES;
}

Answer 4

In Swift 5:
Continuing Talha Rasool's answer, don't forget to delegate self in viewDidLoad function. This will let current MainTabBarController to handle all the delegate methods
import UIKit
class MainTabBarController: UITabBarController, UITabBarControllerDelegate {
override func viewDidLoad() {
super.viewDidLoad()
self.delegate = self // Delegate self to handle delegate methods.
}
func tabBarController(_ tabBarController: UITabBarController, shouldSelect viewController: UIViewController) -> Bool {
let selectedIndex = tabBarController.viewControllers?.firstIndex(of: viewController)!
if selectedIndex == 1{
//Do anything.
return false
}
return true
}
}

Answer 5

When user navigate to payment controller , you can hide the tabbar.
Use this code in your code , when you navigate to another view
yourcontroller.hidebottombarwhenpushed=YES;