CODEWITHSUNDEEP
iosuinavigationcontrolleruitabbarcontroller
Peter Warbo
Peter Warbo

Reputation: 11718

iOS – Showing a view controller already in the navigation stack

This is probably easily sorted but I can't figure it out. I have a tab bar application with two tabs, each tab has a UINavigationController.

Let's say that I in tab 1 push a viewcontroller called ItemViewController, then I go to tab 2. From tab 2 I want to programatically display the ItemViewController. So it should first take me to tab 1 and then display the ItemViewController.

This is easily achievable by just tapping on the tab 1 tab item but I want to do this programtically for other reasons.

What I'm doing right now to achieve this:

[tab1NavController popToRootViewControllerAnimated:NO];
[tabBarController setSelectedIndex:0];
[tab1NavController pushViewController:itemViewController animated:NO];

I would like to be able to do something like this in pseudo-code:

if(viewControllerIWantToDisplayIsOnNavStack)
[tab1NavController presentViewController:viewControllerIWantToDisplay];
else
//instantiate and pushviewcontroller onto stack

How can I achieve this?

Upvotes: 4

Views: 2155

Answers (3)

iMeMyself
iMeMyself

Reputation: 1649

for me following way worked, i used loop to check if class is in stack array

 NSInteger viewControllersCount = 0;
    UIViewController *rootViewController = nil;
    Yourcontroller *viewController = nil;

    NSArray *viewControllers = self.navigationController.viewControllers;

    viewControllersCount = viewControllers.count - 1;

    for (int i = viewControllersCount ; i > 0 ; i--) {
        rootViewController = [viewControllers objectAtIndex:i];
        if([rootViewController isKindOfClass:[Yourcontroller class]])
        {
            viewController = (NWAAccountViewC *)rootViewController;
            [self.navigationController popToViewController:rootViewController animated:YES];
            break;
        }

    }

Upvotes: 1

lawicko
lawicko

Reputation: 7344

// check if the desired controller is on the stack in tab 1
if([[tab1NavController viewControllers] containsObject:viewControllerIWantToDisplay]) {
    // desired controller is on the stack, let's see if it's on top
    if(tab1NavController.topViewController == viewControllerIWantToDisplay) {
        // no need to do anything
        }
    else {
        // we need to pop to the desired view controller
        [tab1NavController popToViewController:viewControllerIWantToDisplay animated:NO];
    }
} else {
    // desired controller not on the stack
    [tab1NavController pushViewController:viewControllerIWantToDisplay animated:NO];
}

So you don't have to pop to root view controller in the tab 1 any more.

Upvotes: 9

Bob de Graaf
Bob de Graaf

Reputation: 2722

it's very easy to programmatically select another tab, just do this:

tabbarcontroller.selectedIndex = tabNr;

But I see you already know this. You can check whether the top view controller on the stack is the type of viewcontroller you need by checking like this: 

if([navigationcontroller.topviewcontroller isKindOfClass:[Yourcontroller class]])
{
    //change tabbar or something else
}

Upvotes: 0

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