i have multiple storyboard in my storyboard. I have embedded the firstVC with navigationcontroller and remaining attached to the firstvc through segues. The remaining VC's are not embedded in navigationcontroller. Now when i click the button to open the next VC without navigation controller. It opens it twice. When i disconnect the segue it does not open the VC. I'm confused that why this is happening so. This is how my UI Looks,
This is how i perform the segue,
self.performSegue(withIdentifier: "GoToNextVC", sender: self)
View Controllers operate on a stack hierarchy. By embedding your first view controller in a UINavigationController and setting that as the Initial View Controller, you're making it the root view controller for the whole stack. The issue you are experiencing is occurring because you are segueing to view controllers without the root view controller's knowledge every time you call performSegue(withIdentifier:sender:). This causes the stack to be out of order and disjointed, preventing you from returning to the previous view controller(s) when calling dismiss(animated:completion:).
Instead of segues, try pushing each view controller to the stack with:
navigationController?.pushViewController(VIEW_CONTROLLER, animated: true)
To use this:
Remove any segues in Interface Builder, they are no longer needed.
Replace VIEW_CONTROLLER with the view controller you want to push.
Related
Here is what I want to do and I am not sure is it right approach, so please give me an advise how to do it.
I have Initial VC with Navigation VC, from it I push First VC, from it I push Second VC.
Next I present (from NavigationController of Second VC) Third VC.
And now I want to remove First and Second VCs from navigation stack.
After that I expect to have such result: I dismiss Third VC and I see Initial VC
How can I get that result?
You can remove view controller from navigation stack by function:
navigationController?.viewControllers.removeAtIndex(*index of view controller you wanna remove*)
You can go back to the initial view controller by calling UINavigationController.popToRootViewController(animated: Bool)
I am interested in segueing from an xib file (when a button is tapped) which is one table view cell from a table view, to another view controller. I am unable to show segue (through main storyboard) because they aren't on the same storyboard. I was wondering if this could be done programmatically, and if so, with what kind of code.
Please let me know if you need more detail.
Your options for programmatically showing a view controller are the following functions
From within a view controller
presentViewController
dismissViewController
From within a view controller on a navigation stack
pushViewController
popToViewController
popToRootViewController
popViewController
Which function to use is determined by the context in which the view controller appears.
For presenting view controllers, if you are working with XIBs and storyboards then the usual pattern is to first instantiate a view controller from the XIB or storyboard and then present it using presentViewController.
An example is
let vc = UIViewController(nibName: "NAME_OF_THE_NIB", bundle: NSBundle.mainBundle())
self.presentViewController(vc, animated: true) {
// Add completion code here.
}
With navigation stacks you can use the convenience functions for pushing and popping view controllers.
To be clear about terminology, none of these methods are considered to be a Segue. That term only applies to moving between view controllers in a storyboard.
If your cell and your view controller are in different storyboards, you can (since iOS 9) use a segue between them with storyboard references.
See Adding a Segue Between Two Storyboards.
If your cell is in its own .xib unfortunately it is not possible to use a segue.
Segue is between view controllers. So you can't do that in xib as it is only views. You should present/push view controllers in table view's view controller. You can get its view controller like this:
tableView.viewController // and then present/push
I have a UINavigationController as my root controller, but then I segue from one view controller to another UINavigationController.
But when segueing from one view controller which is embedded within a UINavigationController to another UINavigationController the push segue comes from the bottom, presuming it is segueing as a popover. I tried using a show detail segue but still not luck.
Why is this occurring and how can I segue from one to the other using a push/replace segue ?
PS: Is this happening because the UINavigationControllers conflict and overrides the segue as a popover ? The reason I am using two separate navigation controllers is because the style from the previous view overrides the style of the detail view, i posted a separate question about that Cannot change style of UINavigationBar when using scrollViewDidScroll on separate View Controller
Push segue occurs only within one navigation controller. It's how it implements 'show' type segue. Making 'show' segue from navigation controller to another navigation controller is not what Xcode drawing tool considered as 'pushing'. It interprets it as popover by default.
I have a basic storyboard setup where I load my NavViewController, which then points to initial view controller. I then have several additional view controllers all daisy chained together via segues in a linear fashion. When I initially launch my application i run the following in my NavControllerViewController.m
(void)viewDidLoad
{
[super viewDidLoad];
NSArray * controllerArray = [self viewControllers];
NSLog(#"view controllers: %#", controllerArray);
}
The log only shows the very first root view controller (the one directly 'connected' to the nav controller). All over view controllers are missing from the stack. I was under the impression that if a view controller was on my storyboard that it would automatically be added to the nav controller?
If this is not correct, would a good alternative be to instantiate each VC, from the calling VC? For example, if I wanted to transition from VC1 to the VC2, would I put the following code in VC1:
UIViewController *vc2 = [self.storyboard instantiateViewControllerWithIdentifier:#"vc2"];
[self pushViewController:vc2 animated:YES];
Or possibly:
[self performSegueWithIdentifier:#"vc2Segue" sender:self];
They are all able to be reached by segues, but they are not instantiated or pushed onto the stack until you segue to them.
You could use the self perform segue tactic, or the push view controller, or, alternatively, if it is in response to a single button click, just control drag from that button to the next view controller and Xcode does all the rest of the work for you.
If I understand your question correctly, you have a storyboard setup looking similar to the below screen shot.When an application loads this storyboard it will definitely have only one view controller in the navigation controller stack and that will be the root view controller.
Because other view controllers are still not pushed into the navigation controller stack.
In the Viewcontroller-1, you could see a button some Action, I have created a push segue from that button to the Viewcontroller-2.Once you tap that button, second view controller will be pushed to the navigation controller stack.
If you print the viewcontrollers count now, you should get the count as 2.
Repeat the same in the View Controller-2, now you can see the count bumps to 3. Because now we have three view controllers pushed into the navigation controller stack.
Press the back button to pop the view controllers and could see the view controllers count coming down, that's because view controllers are now being removed from navigation controller stack.
As AdamG stated, the UIViewControllers will not be pushed on to the stack until you segue to them.
To set a segue, select a UIViewController and control+drag the connection to the target UIViewController. Under the Attributes Inspector tab set the Storyboard Segue Identifier.
To segue to a UIViewController use the method performSegueWithIdentifier:. Before performSegueWithIdentifier: is called prepareForSegue:sender: will be called. This is where you can pass any values that the next UIViewController needs. To check which segue is being called use the segue.identifier property in prepareForSegue:sender:. After that, you can access the destinationViewController property.
If you need to manually instantiate a UIViewController use instantiateViewControllerWithIdentifer:. The identifier can be set under the Identity Inspector tab in the storyboard.
Can someone explain to me what is the exact difference between modal and push segue?
I know that when we use push the segue gets added to a stack, so when we keep using push it keeps occupying memory?
Can someone please show me how these two are implemented?
Modal segues can be created by simply ctrl-click and dragging to destination but when I do that with the push my app crashes.
I am pushing from a button to a UINavigationController that has a UIViewController.
A push Segue is adding another VC to the navigation stack. This assumes that VC that originates the push is part of the same navigation controller that the VC that is being added to the stack belongs to. Memory management is not an issue with navigation controllers and a deep stack. As long as you are taking care of objects you might be passing from one VC to another, the runtime will take care of the navigation stack. See the image for a visual indication:
A modal Segue is just one VC presenting another VC modally. The VCs don't have to be part of a navigation controller and the VC being presented modally is generally considered to be a "child" of the presenting (parent) VC. The modally presented VC is usually sans any navigation bars or tab bars. The presenting VC is also responsible for dismissing the modal VC it created and presented.
Swift 3.0 and XCode 8.2.1 update
1. Push Segue
Push segue has been renamed as Show segue. To create push segue, the parent view controller needs to be embedded in navigation controller. The navigation controller provides navigation bar. Once you connect two view controller with push segue, the child view controller will automatically has navigation bar on top. The child view controller will be added on top of the navigation stack.
Push segue also provides default features. The child view controller will have a back button that gets you back to the parent view controller. You can also swipe right to pop the child view controller. The animation for push segue is like sliding pages horizontally.
While you are allowed to make a push segue from a view controller that is not in a navigation controller, you will lose all the features like navigation bar, animation, gesture etc when you do so. In this case, you should embed your parent view controller inside navigation view controller first and then make push segue to child view controllers.
2. Modal Segue
A modal segue (i.e. present modally), on the other hand, is presenting over the current view controller. The child view controller will not inherit navigation view controller so the navigation bar will be lost if you present modal segue from a view controller with navigation view controller. You have to embed the child view controller in navigation controller again and start a brand new navigation stack if you want it back. If you want to get back to parent view controller, you have to implement this by yourself and call dismiss from code.
Animation for modal segue is that the child view controller will comes up from the bottom of the page. The navigation view controller is also gone in this demo
The push view must be built in a navigationController.
Click on your master view, then in the menu bar choose:
EDITOR->embed in->navigationController
This is pushing controls using custom push and segue methods for storyboard
And Modal is way to navigate through views without using Storyboards.