I have two view controllers - one main VC (ViewController) and this is segue'd to another VC via "Present Modally" (DetailViewController). The ViewController is embedded in Navigation Controller whereas the DetailViewController is not embedded in anything.
In my ViewController I added two functions:
#IBAction func cancelToVC(segue: UIStoryboard) {
}
#IBAction func saveDetails(segue: UIStoryboard) {
}
So now when I go to my DetailViewController I am hoping to connect two bar button items "Cancel" and "Done" to the exit button. But it doesn't even highlight to allow me to select it. Any suggestions?
I think you should set up your IBAction func's like this:
#IBAction func cancelToVC(segue: UIStoryboardSegue) { // Not UIStoryboard
}
Related
I just want to perform segue with a back button on top.
#IBAction func onFirst(_ sender: UIButton) {
performSegue(withIdentifier: "firstSegue", sender: self)
}
#IBAction func onSecond(_ sender: UIButton) {
performSegue(withIdentifier: "secondSegue", sender: self)
}
Let's say you have two view controllers, ViewControllerOne and ViewControllerTwo.
You could do that programmatically or using storyboards.
Since you seem to be using #IBOutlet I will assume you want to do it using storyboards.
First open up your Main.storyboard and make sure that ViewControllerOne (the controller you want to segue from) is embedded in a Navigation Controller.
If it's not, you can do that by clicking on your View Controller, then click on Editor in the top menu bar, go to Embed In and select Navigation Controller.
Then you can create a segue using the Interface Builder by doing control + click on the little yellow icon at the top of ViewControllerOne (not the Navigation Controller) & drag to ViewControllerTwo in the Interface Builder.
Now click on the segue that just got created, and type an identifier of your choice in the Attributes Inspector.
Then in your ViewControllerOne class, you can just perform the segue using the #IBOutlet as you mentioned :
#IBAction func onFirst(_ sender: UIButton) {
performSegue(withIdentifier: "your_segue_identifier", sender: self)
}
Just make sure that the segue identifiers match, and everything should be fine :)
You need redefine target and action for your current navigation item
self.navigationItem.leftBarButtonItem?.target = self
self.navigationItem.leftBarButtonItem?.action = #selector(self.onFirst(_:))
I am creating an application which shows a PageVC: UIPageViewController as intro and guide to app.
After navigating through the intro, a Next Button leads to "SettingsVC" which is used to store default settings for the app.
Settings have to be chosen by the user initially although can be changed later.
PageVC ---> SettingsVC
A Save and a Cancel button on the SettingsVC leads to the MainVC of the app.
A button on MainVC leads to SettingsVC.
SettingsVC <---> MainVC
The app would work as follows:
if isFirstLaunch{
instantiate PageVC
}else{
instantiate MainVC
}
in PageVC
nextButtonPressedinPageVC{
instantiate SettingsVC
}
in SettingsVC
if saveButtonPressed && cameFromPageVC{
instantiate MainVC
}
if cancelButtonPressed && cameFromPageVC {
do Nothing
}
if saveButtonPressed && cameFromMainVC{
dismiss currentVC
}
if cancelButtonPressed && cameFromMainVC {
dismiss currentVC
}
in MainVC
if settingsButtonPressedinMainVC {
instantiate SettingsVC
}
I have made sure that if it is application's first launch, PageVC will be instantiated else MainVC will be instantiated.
How can I move between the viewControllers without a possible memory leak i.e. where to performSegue and where to dismiss current VC?
Please include code for reference.
There are many ways to do this, here is one that I find very straightforward because you can do most of the work in your Storyboard:
Think of your MainVC as the rootViewController and the other two as accessory views that will only temporarily be shown. The MainVC should always be your entry point, so set it as the initial VC in your Storyboard.
The other two should be displayed modally so that you can easily return to the MainVC by dismissing them, no matter how you opened them in the first place.
To do this, draw a segue from your MainVC button to the PageVC and name it "showPageVC". From the Next button in your PageVC, draw another segue to the SettingsVC. Now you need some code to handle the dismiss actions: put this snippet in your MainVC:
#IBAction func unwindToMain(segue:UIStoryboardSegue) {
}
This function is just a marker, so it doesn't need a body. It just enables you to create a unwind segue back to MainVC: For each of the buttons in SettingsVC, hold Ctrl and draw from the button to the right exit icon in the header of the SettingsVC storyboard scene and choose unwindToMain in the tiny black popup.
Now you only have to implement the logic to decide if you want to show the PageVC or not in viewDidAppear() of the MainVC. So the whole code would look something like this:
class MainVC: UIViewController {
var didDisplayPageVC = false
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
if (didDisplayPageVC == false) {
performSegue(withIdentifier: "showPageVC", sender: self)
didDisplayPageVC = true
}
}
#IBAction func unwindToMain(segue:UIStoryboardSegue) {
}
}
The rest is in the storyboard. If this little proof-of-concept is working, you can go and configure the segues (you might want to remove the animation) etc.
I have a container embedded in a ViewController with a navigation bar. The ContainerView contains another ViewController with some textfields.
When the ContainerView is first displayed, the textfields are disabled.
What I would like to do is add an edit button to the navigation bar which enables the textfields.
Basically, is it possible for a bar button item in a viewcontroller to have an action on another view controller displayed in a container?
in this case you can do a little trick
the bar button will be in the ViewController but we can store the content of the ContainerView in a variable in the first ViewController
to do that i would suggest to make the content of the ContainerView has a custom class so you would write a function in it
here is an example on how to catch the content of the ContainerView
class ViewController: UIViewController{
weak var containter: ContainerViewController!
#IBAction func menuAction(_ sender: UIBarButtonItem) {
//do what you want containter.doAction()
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?){
if let vc = segue.destination as? ContainerViewController {
self.containter = vc
}
}
}
Always the case. I've been looking for an answer for hours, as soon as I ask I figure it out.
I'm not sure its the best way to do it but I just made an edit bool controller by the edit button. Then used:
var child = self.childViewControllers[0]
child.viewWillAppear(false)
This reloaded the data and if it was in edit mode enabled the textfields. Works fine!
I have this situation :
I have a first view controller , when tap on button in it I open in modal mode another view controller , in this view controller when I tap another button I open in modal view another view controller and in it there is a button and when I tap on it I want to go to first view controller without re-initialize it.
How do I do it?
This is the perfect situation for an unwind segue.
Put this in your first viewController (the one you want to return to):
#IBAction func backFromVC3(_ segue: UIStoryboardSegue) {
print("We are back in VC1!")
}
Then in the Storyboard in your 3rd viewController, control-drag from your button to the exit icon at the top of the viewController and choose backFromVC3 from the pop-up.
Now, when the user presses the button in VC3, both VC3 and VC2 will be dismissed and you will return to VC1.
If you are not using Storyboards, you can dismiss the viewControllers with code. Here is code for a button's handler to dismiss two levels of viewController:
func doDismiss(_ sender: UIButton) {
// Use presentingViewController twice to go back two levels and call
// dismissViewController to dismiss both viewControllers.
self.presentingViewController?.presentingViewController?.dismiss(animated: true, completion: nil)
}
Thanks all for reply and edited my question :)
I found 2 line code to resolved my problem:
let appDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
appDelegate.window!.rootViewController?.dismissViewControllerAnimated(true, completion: nil).
And that work well.
Thanks very much
I have a navigation controller, with a table view. When I press a cell, the detail view controller opens.
In my root view controller I have :
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "detailview" {
var destination:DetailViewController = segue.destinationViewController as DetailViewController
destination.delegate=self
}
}
In my detail view controller I have a back button :
#IBAction func back() {
self.navigationController?.popViewControllerAnimated(true)
}
The issue is, after 2 go to and return, my app crashes when I go back on the root view controller pressing back button. The console doesn't give me errors. It just crashes.
I think I have forgotten to unwind the segue.
So in my detail view controller I added :
#IBAction func unwindToViewController(segue: UIStoryboardSegue) {
println("unwind function")
}
I connect this function to my back button with "exit" in my storyboard.
When I run my app, If I press on the back button, the console doesn't display my print "unwind function", so unwindToViewController isn't called. Why ?
And my app still crashes...
Your unwindToViewController method should be placed in your root viewController, then ctrl-drag from the button in the detailViewController to the Exit icon in InterfaceBuilder. Choose that method in the popup menu.
Another approach would be to declare a protocol with a function in the rootViewController that is called from the detailViewController. You already set the rootViewController as the delegate of the detailViewController. Within that function you call dismissViewController.
Swift answer...
I had a similar problem.
The func: "segueForUnwindingToViewController(toViewController: UIViewController, fromViewController: UIViewController, identifier: String?) -> UIStoryboardSegue" was never called.
Solution:
since I didn't have a "UINavigationController", because I simply embeded the app in a Navigation Controller, I created a UINavigationController subclass for the Navigation Controller and added the function named above on it. Now the app calls "segueForUnwindingToViewController"