UINavigationController - 使用UIBlurEffect清除背景

Question

我在使用UIBlurEffect的UIViewController中使用了.crossDissolve過渡樣式。 UIViewController在其視圖中添加了一個collectionView，所以它們都有清晰的背景。

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 
    } 
} 

這是結果，你可以看到背後LiveDealCategorySelection的MapView：

問題是，當我嵌入在V一個UINavigationController內觀使用控制器，因爲我不能給它的背景色設置爲.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) 
} 

在LiveDealCategorySelection我想：

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

，我也試圖把背景顏色，當我設置爲.clear實例化導航控制器，但我得到一個黑色的背景。任何想法？

Answer 1

你只是忘了將演示文稿樣式移動到UINavigationController

navContr.modalPresentationStyle = .custom 

Answer 2

隨着導航控制器，你不能達到你想要的。只有Modal的OverCurrentContext呈現，支持從一個視圖控制器到另一個透明或半透明背景的轉換。

如果你想模糊這個視圖控制器的背景，然後使用具有模態呈現呈現這個視圖控制器的「自定義（或過電流情況下）」

別的試試這個：

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) 
}