Set Action for UITabBarItem

Question

How can i set an action for my UITabBarItem ? Can i connect it from storyboard to code somehow? or programmatically? And if so how can it be done?

My hierarchy is UITabBarController -> UINavigationController -> UITabBarItem

Sorry for the noobish question but i really need an answer for this. And I couldn't find anything regarding this online.

Using Swift 3 and Xcode 8

Thank you!

i tired Mannopson's Answer (didn't work):

class BarsViewController: UITableViewController,UISearchResultsUpdating,UISearchBarDelegate,UISearchDisplayDelegate,UITabBarControllerDelegate{

override func viewDidLoad() {
super.viewDidLoad()


self.tabBarController?.delegate = self

        }

func tabBarController(tabBarController: UITabBarController, didSelect viewController: UIViewController) {
            if viewController.tabBarItem.tag == 1 {
                self.tableView.setContentOffset(.zero, animated: true)
            }
        }
        }
                extension UITableView {
                func scrollToTop(animated: Bool) {
                    setContentOffset(CGPoint.zero, animated: animated)
                }
            }

silentBob Answer Didn't Work for me :

class BarsViewController: UITableViewController,UISearchResultsUpdating,UISearchBarDelegate,UISearchDisplayDelegate,UITabBarControllerDelegate{


    override func viewDidLoad() {
        super.viewDidLoad()


    self.tabBarController?.delegate = self
}

func tabBarController(tabBarController: UITabBarController, didSelect viewController: UIViewController) {
        if viewController.tabBarItem.tag == 1 {
            tableView.scrollToRowAtIndexPath(NSIndexPath(forRow: 0, inSection: 0), atScrollPosition: .Top, animated: true)
        }
    }

}

i also tried Tushar Sharma's answer and it didn't work as well.

What Im trying to do is when you are scrolled down in the tableView you will tap the current Tabbaritem the tableView Will scroll to top just like intagram.

Use a tag, and then you can detect which tab bar item is currently selected — Mannopson, Mar 08 '17 at 22:03
Can help me with the code ? I have no idea how im gonna do this... — Newbie Questions, Mar 08 '17 at 22:05
@Mannopson updated question thats what i tried from your answer i try something else all the time but i just can't get it to work — Newbie Questions, Mar 12 '17 at 10:04

Tushar Sharma · Answer 1 · 2017-03-09T03:53:08.093

0

Basically you do this:

1) Make sure your class confirm to the UITabBarDelegate

2) Set tags in IB for each tab bar item

3) Implement the didSelectItem method, something like this:

 class yourclass: UIViewController, UITabBarDelegate {
        func tabBar(tabBar: UITabBar, didSelectItem item: UITabBarItem) {
           if(item.tag == 1) {
       //your code for tab item 1
    }
    else if(item.tag == 2) {
       //your code for tab item 2
    }
        }
    }

edited Mar 09 '17 at 03:53

answered Mar 09 '17 at 03:40

Tushar Sharma

2,839
1
16
38

Thank you for helping! I will test it in a few hours and report back :) – Newbie Questions Mar 09 '17 at 04:12
@Newbie Questions No problem be sure to give tags in IB otherwise it will crash if you tried to access tags directly. – Tushar Sharma Mar 09 '17 at 04:22
@Newbie Questions have you specified tags in storyboard? – Tushar Sharma Mar 09 '17 at 06:21
yep i gave every tabbarbuttonitem a specific tab going from 1 to 4 – Newbie Questions Mar 09 '17 at 06:24
I don't know and cant check at the moment. In a few hours i might be able to. @TusharSharma any idea why its not working? – Newbie Questions Mar 09 '17 at 06:43
@ Newbie Questions can you put a Breakpoint on this function and test what is happening ?? – Tushar Sharma Mar 09 '17 at 06:48
Firslty which function exactly? And secondly not right now but in a few hours. @TusharSharma – Newbie Questions Mar 09 '17 at 06:53
The code isn't breaking or crashing or anything the tab bar scroll to top function is just not working as i wanted it to @TusharSharma – Newbie Questions Mar 09 '17 at 06:54
@ Newbie questions Do this to scroll to top tableView.setContentOffset(CGPointZero, animated:true).But with breakpoint debugging gets much easier.I just want to check is that delegate method is getting called successfully or not. – Tushar Sharma Mar 09 '17 at 07:01
Understood. Will do it when i can @TusharSharma – Newbie Questions Mar 09 '17 at 07:11
i put breakpoints all over but nothing is showing in the debugger – Newbie Questions Mar 09 '17 at 12:53
@Newbie Questions is it getting to that delegate? – Tushar Sharma Mar 09 '17 at 12:55
i seriously get nothing out of the debugger maybe explain more specifically how to set up the breakpoint? Maybe i did it wrong although i added every breakpoint available... – Newbie Questions Mar 09 '17 at 12:56
@Newbie Questions check this and confirm everythingis same.-: http://stackoverflow.com/questions/30378652/open-viewcontroller-from-tab-like-in-instagram-camera-page-on-ios/30379403#30379403 – Tushar Sharma Mar 09 '17 at 13:01
The only thing different is i use tableviewcontroller and not viewcontroller @TusharSharma – Newbie Questions Mar 09 '17 at 13:06
Ok i didn't had the tabbarcontroller delegate let me try and add this. – Newbie Questions Mar 09 '17 at 13:30
because im using a uitableviewcontroller i cant implement uitabbarcontroller protocol...im trying to find a way to reference the tableview in my tableViewController in a new swift file i made and im struggling to do that. – Newbie Questions Mar 09 '17 at 16:10
Do you know a way to reference a tablview from another viewController in a different swift file? – Newbie Questions Mar 09 '17 at 16:11

score 0 · Answer 2 · answered Mar 10 '17 at 02:13

0

I think you'll need to setup UITabBarControllerDelegate protocol. Try this:

class YourClass: YourSuperClass, UITabBarControllerDelegate {

    func tabBarController(_ tabBarController: UITabBarController, didSelect viewController: UIViewController) {
        if viewController.tabBarItem.tag == 1 {
            self.tableView.setContentOffset(.zero, animated: true)
    }
}

    override func viewDidLoad() {
        super.viewDidLoad()

        self.tabBarController?.delegate = self
    }
}

answered Mar 10 '17 at 02:13

Mannopson

2,634
1
16
32

Thanks for helping! I will try this as soon as i get home – Newbie Questions Mar 10 '17 at 08:16
i implemented this in my tableViewController code file. – Newbie Questions Mar 11 '17 at 00:13
Are you set the delegate to self in viewDidLoad? – Mannopson Mar 12 '17 at 01:22
Yep. The delegate is set to self – Newbie Questions Mar 12 '17 at 01:23
You don't need any other scroll functions – Mannopson Mar 12 '17 at 01:38
Are you tried my suggestion? You've not implemented UITabBarControllerDelegate method yet. Take a look my answer. This is work. You don't need UITabBarDelegate method. – Mannopson Mar 12 '17 at 03:00

silentBob · Answer 3 · 2017-03-12T12:04:18.477

0

If you only wish to scroll to top, there is a builtin system option for this, try tapping on status bar.

Edit:

Swift 3:

class ViewController: UITableViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
    }

    override func viewWillAppear(_ animated: Bool) {
        self.tabBarController?.delegate = self
    }
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
}

extension UITableViewController : UITabBarControllerDelegate {
    public func tabBarController(_ tabBarController: UITabBarController, didSelect viewController: UIViewController) {
        tableView.scrollToRow(at: IndexPath(row: 0, section: 0), at: .top, animated: true)
    }

}

Swift 2:

tableView.scrollToRowAtIndexPath(NSIndexPath(forRow: 0, inSection: 0), atScrollPosition: .Top, animated: true)


extension UITableViewController : UITabBarControllerDelegate {
    func tabBarController(tabBarController: UITabBarController, didSelect viewController: UIViewController) {
        tableView.scrollToRowAtIndexPath(NSIndexPath(forRow: 0, inSection: 0), atScrollPosition: .Top, animated: true)
    }
}

Oh, that was a nice lunch :)

Here is an extension for UITableViewController you can use if you wish to scroll to top on every view controller, i'm still playing with it, but i think you can use it.

edited Mar 12 '17 at 12:04

answered Mar 12 '17 at 02:31

silentBob

170
9

Yea i know but instagram has both methods tapping the status bar and the tabbaritem.... i want it as well. – Newbie Questions Mar 12 '17 at 02:33
Here, i've edited my answer, i think this should work for you. Also you have an option to use property instead of tags to get the right item in tabbar. Also scrollRectToVisible is an option. – silentBob Mar 12 '17 at 02:47
can you translate to swift 2.2 ? I'm having troubles to translate that. will be helpful , thank you – Newbie Questions Mar 12 '17 at 10:06
Sure, but i'd advise you to switch to Swift 3 if you can. It won't go backwards, and Swift 4 is in progress already. I think syntax was like this: scrollToRowAtIndexPath(NSIndexPath(forRow: 0, inSection: 0), atScrollPosition: .Top, animated: true) – silentBob Mar 12 '17 at 10:45
I know ... sadly i barely know swift 2.2 and thats what i started with , I'm the most comfortable with this syntax.... i will need a loot of help moving my project to Swift 4 :( im trying to learn by your answers and videos online . Thanks for the translation , i will try it now – Newbie Questions Mar 12 '17 at 10:48
You have some time until that, but it was quite a jump from 2 to 3. Swift 4 shouldn't be that much of a change, that is if you're jumping from Swift 3 ;) – silentBob Mar 12 '17 at 10:49
Updated Question : this is what i have now and it doesn't work for me :( – Newbie Questions Mar 12 '17 at 10:53
There are a lot of sources for learning, here is a link of resources that one guy put up https://www.linkedin.com/pulse/continuous-ios-learning-stefan-sut – silentBob Mar 12 '17 at 10:53

Set Action for UITabBarItem

i tired Mannopson's Answer (didn't work):

silentBob Answer Didn't Work for me :

i also tried Tushar Sharma's answer and it didn't work as well.

3 Answers3

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