Load All TabBar Views

Question

I have a tabbar controller as the root view controller. I would like to pre-load the views of tab [1,2,3] (tab 0 loads as the first tab automatically).

I essentially would like the code in viewdidload to run before the user taps on the tab.

Thanks

score 34 · Accepted Answer · edited Nov 20 '17 at 17:24

34

If you take your view initialization code and move it into loadView instead of viewDidLoad you can force each of the UIViewControllers that are part of your UITabBarController to be loaded by simply calling viewController.view. This happens because a UIViewController will create the view object via the loadView function when asked for it.

for(UIViewController * viewController in  tabBarController.viewControllers){
   viewController.view;
}

or more simply

[tabBarController.viewControllers makeObjectsPerformSelector:@selector(view)];

edited Nov 20 '17 at 17:24

Nik

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answered Feb 08 '12 at 23:10

Joel Kravets

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In the for loop, I think you meant viewController.View. Works! – Laurent May Feb 09 '12 at 03:27
1

And I think you mean @selector(view) in your second option. – Wex Jun 12 '12 at 12:13
+1: Worked for me, with some minor adjustments. I just added `-(void)loadView{[self.tabBarController.viewControllers makeObjectsPerformSelector:@selector(view)];}` to my view controller. – Jezen Thomas Apr 02 '13 at 09:26
Has this changed in iOS 7? – James Moore Jun 12 '14 at 23:55

score 16 · Answer 2 · edited Mar 09 '17 at 11:08

In iOS 8, I created a subclass of UITabViewController named TSMainBarViewController. In the function viewDidLoad of TSMainBarViewController, I just added this code:

for(UINavigationController * viewController in self.viewControllers){
    [[viewController.viewControllers firstObject] view];
}

Then all the viewControllers (root viewController of UINavigationController) will load . All my viewControllers are created in the StoryBoard. Do not implement the function loadView in the UIViewController.

Swift 3 code from EligyD:

for viewController in self.viewControllers! {
    _ = viewController.view
}

score 10 · Answer 3 · answered Dec 18 '15 at 11:20

To handle tab controllers which might or might not have navigation controllers:

viewControllers?.forEach {
    if let navController = $0 as? UINavigationController {
        navController.topViewController?.view
    } else {
        $0.view.description
    }
}

score 2 · Answer 4 · answered May 24 '17 at 11:16

If your all view controllers under the tab bar controller have a navigation bar embedded in them:

Swift 3

for navViewController in self.viewControllers! {
    _ = navViewController.childViewControllers[0].view
}

User Panda's solution didn't work for me.

score 1 · Answer 5 · answered Sep 12 '15 at 20:36

1

if you have UINavigationController before your views

for viewController in self.tabBarController!.viewControllers! {
    var aView = viewController.topViewController as UIViewController
    aView.view.description
}

answered Sep 12 '15 at 20:36

Amr Mohamed

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score 0 · Answer 6 · edited Apr 18 '18 at 19:16

0

Swift 3:

In viewDidLoad() of your UITabBarController

for viewController in self.viewControllers! {
    _ = viewController.view
}

edited Apr 18 '18 at 19:16

Borzh

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answered Feb 01 '17 at 14:09

ElegyD

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score 0 · Answer 7 · answered Jun 06 '21 at 05:33

0

Swift 5:

viewControllers?.forEach {
  if let navController = $0 as? UINavigationController {
     let _ = navController.topViewController?.view
  } else {
      let _ = $0.view.description
    }
 }

answered Jun 06 '21 at 05:33

score -1 · Answer 8 · answered Dec 09 '14 at 18:02

-1

Swift equivalent...

for viewController in self.tabBarController.viewControllers!
{
    viewController.view;
}

answered Dec 09 '14 at 18:02

TWilly

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Load All TabBar Views

8 Answers8

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