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Loading UIViewController "from" Nib File
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Closed 5 years ago.
I have 2 storyboards, I have common screen for both storyboards. I have created it as a separate view controller with xib. I want to load it in between storyboard screens.
You can load VC from Nib file very easily. try the code below :
func presentMyViewController() {
let myVC = MainViewController(nibName:"MyViewController", bundle:nil)
self.navigationController.pushViewController(myVC, true);
// you could present it another way, such as:
// self.presentViewController(myVC, true, nil)
}
Edit : As per comment I don't think that we can directly load xib from story-board but if we need to navigate to xib then you can try above code or else you can also add child view controller directly on viewcontroller.
Something like below:
You can override the loadview() method in class.
public class MyViewController {
override func loadView() {
Bundle.main.loadNibNamed("MyViewController", owner: self, options: [:])
}
//your stuff here...
}
Assumes of course your XIB is MyViewController.xib. Adjust to suit.
edit: also assumes you've correctly set up the files owner references in the XIB (i.e. to the view controller in question).
Related
I am having one view controller which should be hide and show from everywhere in the app without initializing it again. So I just want to know that how can I achieve this. Like by adding that view controller as childView or by presenting it to navigation controller or anything else.
The idea is that the view controller can be shown or hide from any screen of the app.
You can make a view controller as a cocoa touch class... and you can add a xib to it.. once you design the interface for the view controller..
You can make a singleton class and keep the shared instance like this:
class YourViewController: UIViewController {
static let sharedInstance = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "yourStoryBoardId")
}
To show this just do :
func someFunc() {
show(YourViewController.sharedInstance, sender: self)
}
I once did something like this in one of my apps.. i think its a standard approach.
You could also see this for more info and source
I have a UIViewController that looks a bit like this:
class ProfileViewController: UIViewController, UICollectionViewDelegate, UICollectionViewDataSource, ... {
...
convenience init(name: String) {
print("Init with student: \(name)")
self.init()
}
...
}
I have a corresponding Storyboard layout for this, embedded in a UINavigationViewController, linked to a UITabBarController. This seemed like the easiest way to design the layout, and is great for when there's only one instance of this VC required (which is how the app was originally designed).
I'd now like to create multiple tabs from this single design (between 1 and 3), and pass the VC init information programatically, but I'm unsure exactly of the best way to do this - as you can see above I've added a convenience init function based on some reading I've done as that seemed like a good place to start.
It's easy enough to create new named tabs based on the storyboard layout like this:
for user in (users)! {
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let controller = storyboard.instantiateViewController(withIdentifier: "profileNC")
controller.tabBarItem.title = user.name
newTabs?.insert(controller, at: 0)
}
self.viewControllers = newTabs
But, doing it this way I don't get to call the init function to pass the UIViewController the information it needs to display correctly.
How can I create my ViewControllers, link the layout to the Storyboard and use the custom init function? Is this even possible?
Any suggestions gratefully appreciated!!
When using a storyboard you cannot use a custom initialiser. You will need to either set the property directly or use a configuration function on the view controller instance after you have created it.
I currently have three Swift files, one for the main view in a ViewController, and two more which are used for the two views within the first view, which are used for a Segmented Control.
As these don't use segues between each other, I can't use the prepareForSegue method to transfer data between them, so how do transfer the variables and such from one file to another?
This doesn't seem to be a duplicate as other cases such as the one commented are using segues, mine is not.
Are all three Swift classes view controller subclasses?
You have your main view controller with your segmented control. For each segmented, I would create a new view controller subclass.
On your main view controller, for each segment, use a 'Container View' instead of a UIView object.
This will create two new 'screens' in the storyboard, attached to your main view controller with a segue. These new screens will be UIViewControllers, you can change them to be your subclass's as normal.
You can now use your prepareForSegue function as normal to set data in your segmented control view controllers.
So you have something like viewControllerMain, which contains viewSegmentedOne and viewSegmentedTwo, and you want to be able to access `viewControllerMain.myProperty' ?
You can always navigate through the hierarchy to get parent views - but the easiest option could be to include a reference to viewControllerMain in each of the segmented controls
var myParentVC : ViewControllerMain?
then when you create the subviews
mySubView.myParentVC = self
If you are using storyboard for view controllers, then try like this:
let viewController = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "Your_VC_Identifier");
viewController.Your_var = Your_value_to_assign
NOTE: Define Your_var in your ViewController class
You just need to create an instance of the view controller you want to display, this is easy such as calling on the storyboard instance (usually the presenting view controller has one) instantiateViewController(withIdentifier:), by using an identifier that you provide in the storyboard file.
One created you can pass the data you want by casting it to your view controller class and present it as you prefer.
One method would be using singleton class . https://cocoacasts.com/what-is-a-singleton-and-how-to-create-one-in-swift/ this is how you can make singleton class.
other method could be using nsuserdefaults.
You need to decide which approach is best according to your requirement.
try this:
let defaults = UserDefaults.standard()
defaults.set(yourdata, forKey: "someObject")
print(defaults.object(forKey: "someObject"))
You can try use Extensions for UIViewController
private var storedDataKey: UInt8 = 0
extension UIViewController {
var storedViewControllerData: UIViewController? {
get {
return objc_getAssociatedObject(self, &storedDataKey) as? UIViewController
}
set(newValue) {
objc_setAssociatedObject(self, &storedDataKey, newValue, objc_AssociationPolicy.OBJC_ASSOCIATION_ASSIGN)
}
}
}
This very useful you can send data with chain like:
viewControllerB.storedViewControllerData = viewControllerA.storedViewControllerData
or
func viewDidLoad() {
doSomething(self.storedViewControllerData)
}
I am trying to display one view or another view inside the detail view of a master/detail based on a conditional.
These views will contain outlets and elements, so I would like to have view controllers for each that I can play with.
So I created a new UIViewController called AddPhotoViewController. This is how I add AddPhotoViewController.xib inside DetailViewController:
let photoVC = AddPhotoViewController(nibName: "AddPhotoViewController", bundle: nil)
let photoView = photoVC.view
photoVC.delegate = self
photoView.autoresizingMask = UIViewAutoresizing.FlexibleWidth
photoView.frame = area.bounds
area.addSubview(photoView)
The view loads properly in the detail view and looks like this:
AddPhotoViewController.xib's owner class has been set as well here:
When I tap the button, though the action is set properly in AddPhotoViewController to print a message, Xcode crashes.
Am I doing this correctly? Is there a more common practice for loading view X or view Y inside a view controller depending on user data?
Button action:
#IBAction func ButtonPressed(sender: AnyObject) {
println("worked!")
}
Button connection:
Console output:
I think you need to add the viewController:
addChildViewController(PhotoVC)
//and then
PhotoVC.didMoveToParentViewController(self)
I have some problems to use subclasses in Swift, hope someone can help me.
What I have
Two view controllers:
VC1 with just some UIButtons
EffectVC that do some animation depending on the button pressed on VC1
import UIKit
protocol viewAnimation {
func initialStateSet()
func finalStateSet()
}
class EffectVC: UIViewController {
#IBOutlet weak var mainImage: UIImageView!
override func viewDidLoad() {
super.viewDidLoad()
self.initialStateSet()
}
override func viewDidAppear(animated: Bool) {
self.finalStateSet()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
func initialStateSet() {
}
func finalStateSet() {
}
}
class GrowingEffect : EffectVC, viewAnimation {
override func initialStateSet() {
// some stuff
}
override func finalStateSet() {
// other stuff
}
}
The problem
Maybe a simple question but I can't do what I want in Swift: I need to set a subclass according to the button that is pressed.
In other words I need to present subclassed view controller from my VC1 according to which button is pressed on VC1.
If I press the first button for example I want to show the VC 2 with the class GrowingEffect for use some custom stuff (this stuff must change according to the selected button).
What I tried
use IBAction for create my subclassed VC2 and show it
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let destinationViewController : UIViewController = storyboard.instantiateViewControllerWithIdentifier("EffectVC") as! GrowingEffect
self.presentViewController(destinationViewController, animated: true, completion: nil)
but I got
Could not cast value of type 'ViewAnimationDemo.EffectVC'
(0x109948570) to 'ViewAnimationDemo.GrowingEffect' (0x109948650).
use PrepareForSegue
but I can't set any subclass
What I really want to do
I know there are some other solution, like not using storyboard, but now I describe exactly what I want to do, hoping this is possibile:
have only one view controller in IB (EffectVC) associate with the class EffectVC. The class EffectVC has some subclasses like GrowingEffect.
In my code I want to instantiate the view controller EffectVC with the subclass that I need: for example instantiate the view controller in IB EffectVC with the class GrowingEffect.
I know that if I have one view controller for every subclass of EffectVC I can do what I want but I don't want so many view controller in IB because they are equal, the only things that I want to change are 2 methods.
I think there are some things mixed up in your setup. You should have 2 view controllers, each set up in its file, and each present in the storyboard with its identifier. It is ok if GrowingEffect inherits from EffectVC.
What you currently do with as! GrowingEffect is actually trying to cast the UIViewController instance you get from calling instantiateViewControllerWithIdentifier("EffectVC") to GrowingEffect. This will not work, because it is of type EffectVC.
Rather, you need to call instantiateViewControllerWithIdentifier("EffectVC") if button X is pressed, and instantiateViewControllerWithIdentifier("GrowingEffect") if button Y is pressed.
EDIT
If you use storyboard, you have to instantiate view controllers using instantiateViewControllerWithIdentifier. But you can only get an instance of GrowingEffect, if it is present on the storyboard.
It is not possible to "cast" an instance of EffectVC to GrowingEffect once created.
So, you have two possibilities here:
Use storyboard and put both view controllers on it. Use instantiateViewControllerWithIdentifier to instantiate the view controller you need, depending on the button pressed.
Do not use storyboard. Then you can create the needed view controller manually and use your UINavigationController's pushViewController method to present it.
You can't cast from parent class to child class, parent class just doesn't have the capacity to know what the child is doing. You can however cast from a child to parent, so you would want to set your view controller as GrowingEffect, then cast it to Effect, but again there is no strong suit to doing this either unless some method needs the parent class and you are using the child class. It looks like you need a redesign of how you want your view controllers laid out. Now I am assuming you have 2 children, lets call GrowingEffect and ShrinkingEffect. In your designer, you set your 1 to GrowingEffect and the other to ShrinkingEffect and make sure they have unique identifiers. Then you can use your view to present an Effect, and pass in either of those objects.