I´ve a UITabBarController in the middle of a storyboard and I want that when I push back button on UITabBarController (TabBar) sends me to View02 directly.
My sequence is:
NavigationController->UIViewController01-> UIViewController02 -> UIViewController03 -> UITabBarController -> 3 TabBarViews
Could you help me, please?
Thanks in advance,
You have to create an unwind segue. First add a method in the view controller you want to unwind to:
- (IBAction)unwindToMyViewController:(UIStoryboardSegue *)unwindSegue
{
}
Then in a view controller you want unwind from drag from the button to the green exit icon and select your action.
Related
I'm new with IOS and Swift so don't judge if solution is easy.
I have three ViewControllers like A,B and C.
I started from A -> NavigationController -> B -> NavigationController -> C
In specific situation I need to come back from C to A without seeing B. Is any way to do this?
Maybe changing the parent navigationController? Maybe I can print stack with every current view? - it will be really helpful.
I tried dismiss C and B view one by one and it work's but then we can see B view for a moment - so it's not a solution for me.
P.s : I'm using Modal kind to switch between controllers.
enter image description here
If A is always the first view controller, you can just do :
viewcontrollerC.navigationController?.popToRootViewController(animated: true)
This methods pop the stack to the first view controller, without displaying intermediates ones
If A is not the first viewController, you can do :
viewcontrollerC.navigationController?. popToViewController(viewControllerA, animated: true)
If you don't have a reference to viewControllerA, search it in the stack :
let viewControllerA: UIViewController?
for (let vc in (self.navigationController?.viewControllers ?? [])) {
//adust the test to find the appropriate controller
if vc.isKindOf(ViewControllerAClass.self) {
viewControllerA = vc
break
}
}
if let viewControllerA = viewControllerA {
self.navigationController?.popToViewController(viewControllerA, animated: true)
}
source : https://developer.apple.com/documentation/uikit/uinavigationcontroller/1621871-poptoviewcontroller
There are 2 ways you can achieve this. The simple to implement is in View Controller C you can, on in the specific situation, invoke following function:
navigationController?.popToRootViewController(animated: true)
This will pop all the navigational view hierarchy and take you back to the root i.e. the first view controller.
Second approach is to define unwind method in the view controller you want to go back to. In view controller when you start typing unwind, in Xcode 10 you will get autocomplete to add this Swift Unwind Segue Method.
#IBAction func unwindToA(_ unwindSegue: UIStoryboardSegue) {
let sourceViewController = unwindSegue.source
// Use data from the view controller which initiated the unwind segue
}
In this particular question let us say you added this method in View Controller A as you want to go back to it. I assume you have a button on View Controller C to go back to A. Controll+Drag from the button to the Exit symbol of the view controller A. The unwindToA method will automatically pop-up. Connect to it and you are done. When the user presses this button it will go back 2 navigation controllers to A.
Note: By this method you can go back to any navigation controller on the Navigation stack and it is not limited to root view controller alone. Below I am addition picture showing the exit on a view controller.
We have a sequence of screens that navigate in order...
BaseViewController -> A -> B -> BaseViewController
Each screen uses NavigationController.PushViewController to go from...Base->A, A->B. So each subsequent screen is placed in the navigation stack.
So if you are on A and you click 'back', then it goes back one screen. This works well as it is controlled by the NavigationController.
However, when you are on screen B, 'back' should to back to the BaseViewController.
Instead it goes (as designed by Apple) back to A. Is there a way to intercept the 'back' button on B so we can instead use NavigationController.PopToViewController to send the user back to BaseViewController?
As #the4kman mentioned , we can create a custom button to replace the LeftBarButtonItem ,and handle the back event .
ViewDidLoad in B
this.NavigationItem.LeftBarButtonItem =
new UIBarButtonItem("back", UIBarButtonItemStyle.Plain, (sender,e) => {
UIViewController baseVC = NavigationController.ViewControllers[NavigationController.ViewControllers.Length - 3];
NavigationController.PopToViewController(baseVC, true);
});
As #J.C. Chaparro mentioned , remove A from stack .
ViewDidLoad in B
List<UIViewController> list = NavigationController.ViewControllers.ToList<UIViewController>();
list.RemoveAt(list.Count-2);
NavigationController.ViewControllers = list.ToArray();
You can do something like this in B's viewDidAppear function:
guard let navigationController = self.navigationController else {
return
}
navigationController.viewControllers.remove(at: navigationController.viewControllers.count - 2)
This will remove A from the stack, and allow you to go back to BaseViewController from B.
If I understand correctly you want to pop to root view controller from a certain top view controller. One way to do it would be to create a subclass of UINavigationController and override popViewController method where you would check what you have on top at the moment and decide to pop to root or not. Here's an example:
open class CustomNavigationController: UINavigationController {
override open func popViewController(animated: Bool) -> UIViewController? {
if topViewController is BViewController {
return popToRootViewController(animated: animated)?.last
} else {
return super.popViewController(animated: animated)
}
}
}
Approach:
Use child view controllers
Steps:
Create a view controller C which is a subclass of Base
Add A as a child view controller to C
Create a view controller D which is a subclass of Base
Add B as a child view controller to D
Push C to D
Thanks for all the answers. #Cole Xia put me on the right path for our scenario. His technique works, and the following works as well.
Here is the Xamarin code. The technique is to replace the current list of ViewControllers with a new one. Then when 'back' is hit on B, it goes right back to BaseViewController.
var viewControllers = new UIViewController[] { NavigationController.ViewControllers[0], new B() };
NavigationController.SetViewControllers(viewControllers, false);
I have a problem, I want to open two view Controllers on single tab from to different way.
Like:
Login Screen --> Home Screen --> On home screen two button A & B
1 When click on the button A, open A controller on tab controller tab1
2 When click on the button B, open B controller on tab controller tab1
I have 5 tab in tab controller.
Please help me for that issue.
Please refer attached screen for more help.
Thanks,
you can replace ViewController By using this
func tabBarController(tabBarController: UITabBarController, didSelectViewController viewController: UIViewController) -> Bool {
let selectIndex : NSInteger = (tabBarController.viewControllers?.index(of: viewController))!
if (selectIndex == 1) {
let vc = UIViewController() // your new Controller
var allviews = tabBarController.viewControllers
allviews?.remove(at: selectIndex)
allviews?.insert(vc, at: selectIndex)
tabBarController.setViewControllers(allviews, animated: true)
return false;
}
return true;
}
(Please add some more information to your question, or at least code to know what have you tried.)
By your question, It seems you need a Tab Bar Controller.
You use tab bar controller to organize your app into one or more distinct modes of operation. The view hierarchy of a tab bar controller is self contained. It is composed of views that the tab bar controller manages directly and views that are managed by content view controllers you provide. Each content view controller manages a distinct view hierarchy, and the tab bar controller coordinates the navigation between the view hierarchies.
I have the following setup
-> Navigation Controller -> View Controller A -> View Controller B
B has some left and right navigation items which show up in this sequence
I have another flow where
-> Navigation Controller -> View Controller A -> View Controller C -> View Controller B
In ViewController C, when a save button is sliced, I manually trigger the segue to show View B. But, in this scenario, the navigation bar does not show up.
If I embed controller B in a navigation controller, then in the prepareFor Segue of Controller C, I cannot refer this as the destination. How do I fix this?
I am putting in some screen shots of the settings below:
This is the nav bar in A
The segue from A->B. This is triggered by selecting a row in a table View
This is how the nav bar in B looks when triggered from A
The segue from A->C
This is the nav bar in C
The segue from C->B
From C to B, I am triggering the segue as below:
dispatch_async(dispatch_get_main_queue(), {
self.performSegueWithIdentifier("SegueGroupView", sender: self)
})
On this trigger, the nav bar in B is not appearing
Below is a great answer of how to use Apple's unwind segue.
What are Unwind segues for and how do you use them?
My problem with the answer however is that you have to explicitly tell storyboard which view controller you want to exit (unwind) back to. What I'm trying to do is exit (unwind) back to whichever view controller called it, only using one button.
Let's say I have 3 view controllers: Red, Blue, and Yellow.
Both Red and Blue have a button on them to go to the Yellow view controller, but Yellow only has one button, return. Is it possible to have the yellow return button unwind back to whichever view controller called it?
thanks to #luk2302 I was able to figure it out. No need to even use unwind segue. Thanks luk2302!
#IBAction func returnViewController(sender: AnyObject) {
if((self.presentingViewController) != nil){
self.dismissViewControllerAnimated(true, completion: nil)
}
}