Can't dismiss ModalViewController - swift

Question

I've got a problem by dismissing a ViewController programmatically.
I connected both Controllers and if I press the Button, the Controller will be presented.
Here is my prepareForSegue method:
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
let VC = VC()
let blurEffect = UIBlurEffect(style: UIBlurEffectStyle.Dark)
let blurredView = UIVisualEffectView(effect: blurEffect)
blurredView.frame = CGRect(x: 0, y: 0, width: self.view.frame.width, height: self.view.frame.height + 64)
VC.view.frame = self.view.bounds
VC.view.backgroundColor = UIColor.clearColor()
VC.view.addSubview(blurredView)
VC.modalPresentationStyle = UIModalPresentationStyle.OverCurrentContext
var masterViewOfVC = (segue.destinationViewController as! SubjectSelectionViewController).masterView
blurredView.addSubview(masterViewOfVC)
masterViewOfVC.setTranslatesAutoresizingMaskIntoConstraints(false)
let views = ["masterView": masterViewOfVC]
let horizontalConstraintsForMasterView = NSLayoutConstraint.constraintsWithVisualFormat("H:|[masterView]|", options: .AlignAllCenterY, metrics: nil, views: views)
blurredView.addConstraints(horizontalConstraintsForMasterView)
let verticalConstraintsForMasterView = NSLayoutConstraint.constraintsWithVisualFormat("V:|[masterView]|", options: .AlignAllCenterX, metrics: nil, views: views)
blurredView.addConstraints(verticalConstraintsForMasterView)
(segue.destinationViewController as! VC).viewDidLoad()
self.presentViewController(VC, animated: true, completion: nil)
}
So and if I try to dismiss it it doesn't do anything. I already checked if the buttons works and it does.
Here is my code from the other controller:
//viewDidLoad
cancelButton.setTitle("Abbrechen", forState: UIControlState.Normal)
cancelButton.tintColor = UIColor.whiteColor()
cancelButton.addTarget(self, action: Selector("buttonAction:"), forControlEvents: UIControlEvents.TouchUpInside)
cancelButton.enabled = true
//my function
func buttonAction(sender:UIButton!) {
VC().dismissViewControllerAnimated(true, completion: nil)
}
UPDATE
I delete the segue in my Storyboard and I created a modal segue in the IBAction of my Button. I also initialise my "dismiss button" in this action.
Here is my code from the parentViewController:
#IBAction func SubjectSelctionButtonPressed(sender: UIBarButtonItem) {
let subjectSelectionViewController = SubjectSelectionViewController()
let blurEffect = UIBlurEffect(style: UIBlurEffectStyle.Dark)
let blurredView = UIVisualEffectView(effect: blurEffect)
blurredView.frame = CGRect(x: 0, y: 0, width: self.view.frame.width, height: self.view.frame.height + 64)
subjectSelectionViewController.view.frame = self.view.bounds
subjectSelectionViewController.view.backgroundColor = UIColor.clearColor()
subjectSelectionViewController.view.addSubview(blurredView)
subjectSelectionViewController.modalPresentationStyle = UIModalPresentationStyle.OverCurrentContext
var masterViewOfSubjectSelection = SubjectSelectionViewController().masterView
var buttonOfSubjectSelection = SubjectSelectionViewController().cancelButton
buttonOfSubjectSelection.setTitle("Abbrechen", forState: UIControlState.Normal)
buttonOfSubjectSelection.tintColor = UIColor.whiteColor()
buttonOfSubjectSelection.addTarget(self, action: Selector("buttonAction:"), forControlEvents: UIControlEvents.TouchUpInside)
blurredView.addSubview(masterViewOfSubjectSelection)
masterViewOfSubjectSelection.addSubview(buttonOfSubjectSelection)
masterViewOfSubjectSelection.setTranslatesAutoresizingMaskIntoConstraints(false)
let views = ["masterView": masterViewOfSubjectSelection]
let horizontalConstraintsForMasterView = NSLayoutConstraint.constraintsWithVisualFormat("H:|[masterView]|", options: .AlignAllCenterY, metrics: nil, views: views)
blurredView.addConstraints(horizontalConstraintsForMasterView)
let verticalConstraintsForMasterView = NSLayoutConstraint.constraintsWithVisualFormat("V:|[masterView]|", options: .AlignAllCenterX, metrics: nil, views: views)
blurredView.addConstraints(verticalConstraintsForMasterView)
self.presentViewController(subjectSelectionViewController, animated: true, completion: nil)
}
and the action from the button looks like this:
func buttonAction(sender:UIButton!) {
dismissViewControllerAnimated(true, completion: nil)
}
ok now, when the controller is presenting there is nothing except my elements which I created in the action. My viewDidLoad() method of my presenting Controller is called but the constraints and the formattings doesn't get called...
Here is my viewDidLoad() of my modalViewController:
titleLabel.setTranslatesAutoresizingMaskIntoConstraints(false)
cancelButton.setTranslatesAutoresizingMaskIntoConstraints(false)
separatorLine.setTranslatesAutoresizingMaskIntoConstraints(false)
subjectsTableView.setTranslatesAutoresizingMaskIntoConstraints(false)
subjectsTableView.delegate = self
titleLabel.text = "Unterrichtsfächer"
titleLabel.textColor = UIColor.whiteColor()
titleLabel.font = UIFont(name: "HelveticaNeue-Medium", size: 17)
separatorLine.backgroundColor = UIColor.whiteColor()
subjectsTableView.backgroundColor = UIColor.clearColor()
masterView.addSubview(titleLabel)
masterView.addSubview(cancelButton)
masterView.addSubview(separatorLine)
masterView.addSubview(subjectsTableView)
let views = ["line": separatorLine, "title": titleLabel, "button": cancelButton, "table": subjectsTableView]
let verticalConstraintsForElements = NSLayoutConstraint.constraintsWithVisualFormat("V:|-64-[line(2)][table]|", options: .AlignAllCenterX, metrics: nil, views: views)
masterView.addConstraints(verticalConstraintsForElements)
let horizontalConstraintsForSeparatorLine = NSLayoutConstraint.constraintsWithVisualFormat("H:|[line]|", options: .AlignAllCenterY, metrics: nil, views: views)
masterView.addConstraints(horizontalConstraintsForSeparatorLine)
let horizontalConstraintsForTableView = NSLayoutConstraint.constraintsWithVisualFormat("H:|[table]|", options: .AlignAllCenterY, metrics: nil, views: views)
masterView.addConstraints(horizontalConstraintsForTableView)
let verticalConstraintsForTitleLabel = NSLayoutConstraint.constraintsWithVisualFormat("V:[title(21)]-11-[line]", options: .AlignAllCenterX, metrics: nil, views: views)
masterView.addConstraints(verticalConstraintsForTitleLabel)
let horizontalAlignmentForTitleLabel = NSLayoutConstraint(item: titleLabel, attribute: NSLayoutAttribute.CenterX, relatedBy: .Equal, toItem: masterView, attribute: .CenterX, multiplier: 1, constant: -18)
masterView.addConstraint(horizontalAlignmentForTitleLabel)
let widthForTitleLabel = NSLayoutConstraint(item: titleLabel, attribute: .Width, relatedBy: .Equal, toItem: nil, attribute: .NotAnAttribute, multiplier: 1, constant: 137)
masterView.addConstraint(widthForTitleLabel)
let verticalConstraintsForCancelButton = NSLayoutConstraint.constraintsWithVisualFormat("V:[button(30)]-6-[line]", options: .AlignAllCenterX, metrics: nil, views: views)
masterView.addConstraints(verticalConstraintsForCancelButton)
let horizontalConstraintsForCancelButton = NSLayoutConstraint.constraintsWithVisualFormat("H:[button(90)]-7-|", options: .AlignAllCenterY, metrics: nil, views: views)
masterView.addConstraints(horizontalConstraintsForCancelButton)
Can anybody help me?
Thank you very much!!!

Answer 1

Your problem is that you are not pushing the other view to dismiss it, you are just adding the new view controller on top of the other view
You need to substitute this line
blurredView.addSubview(masterViewOfVC)
For
presentViewController(masterViewOfVC, animated: true, completion: nil)
Now when you call dismiss view controller all should just work

Answer 2

I haven't really checked all your code but to fix it quickly, you can make the instance of VC a class property.
So it'll look something like this:
class MainViewController: UIViewController {
var VC = UIViewController() // I would use an optional here but I've been down voted for suggesting people to use optionals.
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
VC = VC()
// Your code
}
func buttonAction(sender:UIButton!) {
VC.dismissViewControllerAnimated(true, completion: nil)
}
}
Here I'm assuming you're using some kind of master - detail view so buttonAction is still accessible when you segue to VC.
If buttonAction is a method in VC itself, then just call dissmissViewControllerAnimated() on self with:
func buttonAction(sender:UIButton!) {
dismissViewControllerAnimated(true, completion: nil)
}
Either way, you'll have to call dissmissViewControllerAnimated() on the instance of VC. With VC() you'll just create a new instance which has "nothing" to do with the one that already exists.
Update:
If you've created SubjectSelectionViewController() in your storyboard, then you probably would want to instantiate it with:
let storyboard = UIStoryboard(name: "Main", bundle: NSBundle.mainBundle())
let subjectSelectionViewController = storyboard.instantiateViewControllerWithIdentifier("YourIdentifier") as! SubjectSelectionViewController