CODEWITHSUNDEEP
iosswiftswift3uinavigationcontrolleruiblureffect
Mat
Mat

Reputation: 6324

UINavigationController - clear background using UIBlurEffect

I am using UIBlurEffect in a UIViewController which is presented with a .crossDissolve transition style. The UIViewController has a collectionView added to its view so both have a clear background.

HomeViewController.swift

func showLiveDealsCategory(sender:UITextField){
    let catSelection = LiveDealCategorySelection()
    //let navContr = UINavigationController(rootViewController: catSelection)
    catSelection.modalPresentationStyle = .custom
    catSelection.modalTransitionStyle = .crossDissolve
    self.present(catSelection, animated: true, completion: nil)
}

LiveDealCategorySelection.swift

func setupBackgroundView(){
    if !UIAccessibilityIsReduceTransparencyEnabled() {
        self.view.backgroundColor = .clear
        let blurEffect = UIBlurEffect(style: UIBlurEffectStyle.dark)
        let blurEffectView = UIVisualEffectView(effect: blurEffect)
        blurEffectView.frame = (self.view?.bounds)!
        blurEffectView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
        self.view?.addSubview(blurEffectView)
    } else {
        self.collectionView?.backgroundColor = UIColor.black
    }
}

This is the result where you can see the mapView behind LiveDealCategorySelection:

enter image description here

The problem is when I embed the view controller inside a UINavigationController because I am not able to set its background color to .clear:

func showLiveDealsCategory(sender:UITextField){
        let catSelection = LiveDealCategorySelection()
        let navContr = UINavigationController(rootViewController: catSelection)
        catSelection.modalPresentationStyle = .custom
        catSelection.modalTransitionStyle = .crossDissolve
        self.present(navContr, animated: true, completion: nil)
}

In LiveDealCategorySelection I tried:

 override func viewWillAppear(_ animated: Bool) {
        if self.navigationController != nil {
            self.navigationController!.view.backgroundColor = .clear
            self.navigationController!.view.tintColor = .clear
        }
  }

and I also tried to set the background color to .clear when I instantiate the navigation controller but I get a black background. Any idea?

Upvotes: 1

Views: 1281

Answers (2)

Krunal
Krunal

Reputation: 79696

With navigation controller you cannot achieve that you want. Only Modal presentation with OverCurrentContext, supports transition from one view controller to another with clear or semi transparent background.

If you want blur background for this view controller then present this view controller using modal presentation with 'custom (or over current context)'

else try this:

func showLiveDealsCategory(sender:UITextField){
        let catSelection = LiveDealCategorySelection()
        let navContr = UINavigationController(rootViewController: catSelection)
        navContr.modalPresentationStyle = .custom  // << Mark this update
        catSelection.modalPresentationStyle = .custom
        catSelection.modalTransitionStyle = .crossDissolve
        self.present(navContr, animated: true, completion: nil)
}

Upvotes: 0

MarioBajr
MarioBajr

Reputation: 61

You just forgot to move the presentation style to the UINavigationController

navContr.modalPresentationStyle = .custom

Upvotes: 2

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