I have a tabBar with one item at the moment. For this Item I have a ViewController.
Now I would like to dynamically add more items to the tabbar which should all open the same ViewController. I will check inside the viewcontroller which button was pressed and customizie the content.
How can I add more items to the tabbar linking to the same Viewcontroller?
I tried to just add UITabBarItems as a list but this does not work out.
Any advice?
Although I don't like your original idea of multiple SAME VC in the tabController, actually it is feasible.
import UIKit
class MyTabViewController : UIViewController{
override var tabBarItem: UITabBarItem!{
get{ return UITabBarItem.init(title: "temp", image: nil, tag: 100) }
set{ super.tabBarItem = newValue} }
}
class MyTabController: UITabBarController {
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
perform(#selector(change), with: nil, afterDelay: 3.0)
perform(#selector(printViewController), with: nil, afterDelay: 5.0)
}
#objc func printViewController(){
print (viewControllers!)
}
#objc func change(){
if let viewController = self.viewControllers?[0]{
let label = UILabel.init(frame: CGRect.init(x: 0, y: 0, width: 100, height: 100))
label.text = "testing"
viewController.view.addSubview(label)
setViewControllers([viewController,viewController,viewController,viewController,viewController], animated: true)
}
}
}
After 5 seconds, you can see you got 5 same vc in your tabController.
You should be able to subclass UITabBarController and use the viewControllers property or the setViewController(_:animated:) method in viewDidLoad. I'd recommend using a .nib for laying ViewController out, and instantiating it using init(nibName: String?, bundle: Bundle?).
Instead of having the ViewController determine configuration based on it's tabBarItem property, you should have that configuration occur before setting the viewController property on your UITabBarController.
Something like so:
class TabBarController: UITabBarController {
override func viewDidLoad() {
super.viewDidLoad()
var controllers = [UIViewController]()
let firstViewController = ViewController(nibName: "NIBNAME", bundle: Bundle.main)
// Configure unique properties for firstViewController here, including
// the tabBarItem.
controllers.append(firstViewController)
// Configure the rest of the ViewControllers with unique properties and add them to controllers
setViewControllers(controllers, animated: false)
}
}
Also, note that if you have more than 5 controllers you will need to utilize the moreNavigationController property in your UITabBarController subclass.
I recommend you read the documentation for UITabBarController to get an idea on how to do all of this.
Related
I'm basically trying to create a custom UITabBarController since I need some specific functionality. The TabBar itself is done and working, but I don't quite know how to display ViewControllers in this CustomTabBarViewController itself.
Assuming i have the following method:
func tabSelected(_ index: Int) {}
and knowing the height of my TabBar through tabbar.frame.size, how do I instantiate two ViewControllers above the TabBar and switch between them when the tabSelected method is called? A transition animation would be even nicer, but not really necessary.
NOTE: my TabBar doesn't inherit from UITabBarController, only from the regular UIViewController, to avoid further confusion.
Here I created sample project:
CustomTabBarViewController
You should have container view for child ViewControllers
Then you should have array with embed ViewControllers
You should call method in
CustomTabBarViewController which change ViewController inside
container view to ViewController from array of VCs at index which you pass as parameter of this method
Start with declaring outlet collection for your TabBar buttons and also get reference for container view where your ViewControllers will be showed
#IBOutlet var tabBarButtons: [UIButton]!
#IBOutlet weak var container: UIView!
then create array for your tab bar items
var items: [UIViewController]?
next create lazy variables for your controllers
private lazy var aVC: A = {
let storyboard = UIStoryboard(name: "Main", bundle: nil)
return storyboard.instantiateViewController(withIdentifier: "a") as! A
}()
private lazy var bVC: B = {
let storyboard = UIStoryboard(name: "Main", bundle: nil)
return storyboard.instantiateViewController(withIdentifier: "b") as! B
}()
.... this can be simplified by creating method which returns ViewController depending on VC’s identifier
After that append ViewControllers to your items array and also each add as child of your TabBarViewController
override func viewDidLoad() {
super.viewDidLoad()
items = [aVC, bVC]
items!.forEach { addChild($0) }
}
continue with declaring method for setting ViewController
private func setViewController(_ viewController: UIViewController) {
items!.forEach { $0.view.removeFromSuperview(); $0.willMove(toParent: nil) }
container.addSubview(viewController.view)
viewController.view.frame = container.bounds
viewController.view.autoresizingMask = [.flexibleWidth, .flexibleHeight]
viewController.didMove(toParent: self)
}
now add action for your tab bar buttons and get index of button. Then with this index call your tabSelected method
#IBAction func buttonPressed(_ sender: UIButton) {
if let index = tabBarButtons.index(of: sender) {
tabSelected(index)
}
}
inside tabSelected set VC from items depending on index of sender tab bar button
func tabSelected(_ index: Int) {
if let item = items?[index] {
setViewController(item)
}
}
finally in viewDidLoad set first item
override func viewDidLoad() {
...
tabSelected(0)
}
Now you can fully customize your ViewController and make other epic stuff which you know from UITabBarController
Here's another approach:
1. In your CustomTabBarViewController define an array to hold the ViewControllers:
var viewControllers: [UIViewController]
Instantiate the view controllers and add them to the array:
// If you're not using storyboard:
let homeViewController = HomeViewController()
// If using storyboard:
let searchViewController = storyboard.instantiateViewController(withIdentifier: "SearchViewController")
viewControllers = [homeViewController, searchViewController, ...]
2. Define a variable to keep track of the tab button that is selected:
var selectedIndex: Int = 0
3. Implement your tabSelected method like so. I've explained each line in code:
func tabSelected(_ index: Int) {
let previousIndex = selectedIndex
selectedIndex = index
// Use previousIndex to access the previous ViewController from the viewControllers array.
let previousVC = viewControllers[previousIndex]
// Remove the previous ViewController
previousVC.willMove(toParentViewController: nil)
previousVC.view.removeFromSuperview()
previousVC.removeFromParentViewController()
// Use the selectedIndex to access the current ViewController from the viewControllers array.
let vc = viewControllers[selectedIndex]
// Add the new ViewController (Calls the viewWillAppear method of the ViewController you are adding)
addChildViewController(vc)
vc.view.frame = contentView.bounds
// contentView is the main view above your tab buttons
contentView.addSubview(vc.view)
// Call the viewDidAppear method of the ViewController you are adding using didMove(toParentViewController: self)
vc.didMove(toParentViewController: self)
}
I'm new to Xcode/Swift. I have a center button I want to present a modal view from the current view (tab).
I've implemented a custom class for UITabBar that adds that button according to this guide.
This UITabBar has no view controller in self that I can find, so I get an error when I try to present a view.
Error: Value of type 'MainTabBar' has no member 'present'
Is there a way I can have this button present modal from the current view?
I'm not sure how to reach the current view from this custom class.
Should I point the button's addTarget to a uitabbar Delegate and watch for it in my other views?
Should I stop doing this and just do tabs with a tab that pulls up my modal view in a ViewDidAppear() on a different view?
I think I lose the ability to pop, or dismiss, back to the last view if I do that.
Here's the custom UITabBar class I'm working with.
class MainTabBar: UITabBar {
private var middleButton = UIButton()
override func awakeFromNib() {
super.awakeFromNib()
setupMiddleButton()
}
func setupMiddleButton() {
middleButton.frame.size = CGSize(width: 70, height: 70)
middleButton.backgroundColor = .blue
middleButton.layer.cornerRadius = 35
middleButton.layer.masksToBounds = true
middleButton.center = CGPoint(x: UIScreen.main.bounds.width / 2, y: 0)
middleButton.addTarget(self, action: #selector(test), for: .touchUpInside)
addSubview(middleButton)
}
#objc func test() {
let vc = createController()
vc.modalTransitionStyle = .crossDissolve
self.present(vc, animated: true, completion: nil)
}
}
Found a better implementation.
Created a custom class inherited from UITabBarController and named it MainViewController.
Setup the middle button in that controller instead of in the MainTabBar custom class.
self now has member present.
#objc func test() {
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let vc =
storyboard.instantiateViewController(withIdentifier: "createModal") as! createController
self.present(vc, animated: true, completion: nil)
}
https://github.com/drrost/Custom-Tabbar-Cetner-Button
I added 2 tabBar items from storyboard and one UITabBarItem - Menu programmatically. I am successfully able to open the controllers corresponding to tabBarItems which I created using storyboard. However, when I click on "Menu" a blank black screen appears,
#objc public class MainScreenTabsController : UITabBarController {
public override func viewDidLoad() {
super.viewDidLoad()
let tabController = MyViewController()
let tabBarItem = UITabBarItem(title: "Menu", image: UIImage(named: "more-options.png"), selectedImage: UIImage(named: "more-options"))
tabController.tabBarItem = tabBarItem
var array = self.viewControllers
array?.append(tabController)
self.viewControllers = array
}
public func tabBarController(_ tabBarController: UITabBarController, shouldSelect viewController: UIViewController) -> Bool {
return true;
}
public override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
}
}
I followed couple of tutorials for adding tab bar item but all of them had the code I wrote. Am I missing out something very basic?
EDIT:
Class for Menu Controller
#objc public class MyViewController:UIViewController {
public override func viewDidLoad() {
super.viewDidLoad()
}
public override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
}
}
Your app is doing exactly what your code is telling it to do. You are creating an instance of MyViewController and adding it to the UITabBarController's array of View Controllers.
Your MyViewController class file simply defines a blank, black view.
I'm guessing you created a ViewController in your Storyboard that you want to use as MyViewController? If so, you need to instantiate that from the storyboard.
When you're editing your storyboard, assign the MyViewController class to the VC you want to use, and also give it a Storyboard ID - such as MyVC. Then, edit your viewDidLoad function to this:
public override func viewDidLoad() {
super.viewDidLoad()
// wrong way
// let tabController = MyViewController()
if let tabController = storyboard?.instantiateViewController(withIdentifier: "MyVC") as? MyViewController {
let tabBarItem = UITabBarItem(title: "Menu", image: UIImage(named: "more-options.png"), selectedImage: UIImage(named: "more-options"))
tabController.tabBarItem = tabBarItem
var array = self.viewControllers
array?.append(tabController)
self.viewControllers = array
}
}
Since you're creating the ViewController programatically ie. without nib/storyboard, you are responsible for instantiating a UIView object and setting the view property of the view controller. to do that implement the loadView method and assign the view object to view property of the viewController. then you can add custom views to the view object, check the code below.
class MyViewController: UIViewController {
override func loadView() {
// super.loadView() // DO NOT CALL SUPER
//create view
view = UIView()
view.backgroundColor = UIColor.white
//Add a custom view with red color
let customView = UIView()
customView.translatesAutoresizingMaskIntoConstraints = false
customView.backgroundColor = UIColor.red
view.addSubview(customView)
NSLayoutConstraint.activate(
[customView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
customView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
customView.topAnchor.constraint(equalTo: view.topAnchor),
customView.bottomAnchor.constraint(equalTo: view.bottomAnchor)]
)
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
}
It would be good to use Storyboard/Nib for this purpose as you can easily configure custom views/controls using the autolayout in interface builder rather than doing it programmatically. :)
Edit:
if your'e using storyboard then instantiate view controller like given in below code
class MainScreenTabsController: UITabBarController, UITabBarControllerDelegate {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
let tabController = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "MainViewController") as! MainViewController //if using storyboard
let icon = UITabBarItem(title: "Menu", UIImage(named: "more-options.png"), selectedImage: UIImage(named: "more-options")))
tabController.tabBarItem = icon
var controllers = self.viewControllers
controllers?.append(tabController)
self.setViewControllers(controllers!, animated: true)
}
}
I am relatively new to swift and iOS and can't find an answer or any help for my problem that works.
I want to create a navigation controller view when I click on a button in my previous view. My previous view is an on-boarding with a button on the last page. I successfully connected the button to my next view but I am not able to make the view act like a navigation controller. For example, when a navigation bar is displayed, I am not able to add navigation items to it.
Is there a way to set the new view I create by clicking my button in the first view to be the root controller for my navigation view?
A short version of my code:
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
let button = UIButton(frame: CGRect(x: view.frame.width / 2, y: view.frame.height / 2, width: 40, height: 40))
button.backgroundColor = .red
button.tintColor = .white
button.setTitle("Test", for: .normal)
button.addTarget(self, action: #selector(change), for: .touchUpInside)
view.addSubview(button)
}
func change () {
let otherView = SecondViewController()
self.present(otherView, animated: true, completion: nil)
}
}
class SecondViewController: UINavigationController {
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .yellow
}
}
The SecondViewController gets displayed with a navigation bar but I had problems implementing navigation items, because they weren't shown.
Does the second view controller I present have to be of type UIViewController or UINavigationController?
I am aware that there are easier ways to achieve my goal with the use of the storyboard but in my opinion I understand it better by making my own references via code instead of creating them by dragging them out of the storyboard.
Edit: I have no Objective-C background and learning Swift for about 4 weeks now.
You can add UINavigationController like below :
First you have to create object of SecondViewController,
let myViewController: SecondViewController? = storyboard?.instantiateViewController(withIdentifier: "SecondViewController")
Or
let myViewController: SecondViewController? = SecondViewController(nibName: "SecondViewController", bundle: nil)
Or
let myViewController: SecondViewController? = SecondViewController()
Then add Navigation to SecondViewController
let myNavigationController = UINavigationController(rootViewController: myViewController!)
If you want to present then use :
self.present(myNavigationController, animated: true) {
}
If you want to push then use :
self.navigationController?.pushViewController(myNavigationController, animated: true)
If you want to set as root controller then use :
let appDelegate: AppDelegate = (UIApplication.shared.delegate as? AppDelegate)!
appDelegate.window?.rootViewController = myNavigationController
var objVC: UIViewController? = storyboard.instantiateViewController(withIdentifier: "ViewController")
var aObjNavi = UINavigationController(rootViewController: objVC)
Now, instead of using view controller object use navigation controller object.
Ok stuck on this one, help would be most appreciated.
So I have a tab controller inside a navigation controller in my storyboard.
Then I have two view controllers with nib files that I want to load into the tab controller programmatically. I'm using the following code but getting a blank screen when I load the app.
class MainTabBarController: UITabBarController, UITabBarControllerDelegate {
override func viewDidLoad() {
super.viewDidLoad()
delegate = self
}
override func viewDidAppear(animated: Bool) {
super.viewWillAppear(animated)
let verbViewController = VerbViewController(nibName: "VerbViewController", bundle: nil)
let communityViewController = CommunityViewController(nibName: "CommunityViewController", bundle: nil)
let tabIcon1 = UITabBarItem(title: nil, image: UIImage(named: "VerbTab"), tag: 0)
let tabIcon5 = UITabBarItem(title: nil, image: UIImage(named: "CommunityTab"), selectedImage: nil)
verbViewController.tabBarItem = tabIcon1
communityViewController.tabBarItem = tabIcon5
let tabControllers = [verbViewController, communityViewController]
self.tabBarController?.setViewControllers(tabControllers, animated: true)
self.viewControllers = tabControllers
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
// MARK: - Delegate method
func tabBarController(tabBarController: UITabBarController, shouldSelectViewController viewController: UIViewController) -> Bool {
return true
}
}
You are calling self.tabBarController from within a UITabBarController which doesn't make much sense.
UIViewController's tabBarController returns "The nearest ancestor in the view controller hierarchy that is a tab bar controller." which in your case is probably nil because your tab bar controller is not contained in yet another tab bar controller.
You probably want to just call self.setViewControllers directly.
This behavior would also probably make more sense in viewDidLoad rather than viewWillAppear, do you really want to replace the controllers for each tab every time the tab bar appears?