导航栏的实时模糊效果

Question

如何实现导航栏的实时模糊效果，就像 iPhone 中的 Trailers 应用一样。

即，当您滚动时，导航栏后面的内容应该会变得模糊。 请帮我一些代码。

谢谢！

我想达到这样的效果：-

Answer 1

从 iOS 8.0 版本开始，Apple 引入了新的类UIVisualEffectView 等，以在视图上添加半透明和模糊效果。

在这里，您可以如何使用它为导航栏或任何其他UIView添加模糊效果：

斯威夫特 5

func addBlurEffect() {
    let bounds = self.navigationController?.navigationBar.bounds
    let visualEffectView = UIVisualEffectView(effect: UIBlurEffect(style: .light))
    visualEffectView.frame = bounds ?? CGRect.zero
    visualEffectView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
    self.navigationController?.navigationBar.addSubview(visualEffectView)        

    // Here you can add visual effects to any UIView control.
    // Replace custom view with navigation bar in the above code to add effects to the custom view.
}

目标 C 代码：

- (void) addBlurEffect {
    // Add blur view
    CGRect bounds = self.navigationController.navigationBar.bounds;
    UIVisualEffectView *visualEffectView = [[UIVisualEffectView alloc] initWithEffect:[UIBlurEffect effectWithStyle:UIBlurEffectStyleLight]];
    visualEffectView.frame = bounds;
    visualEffectView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
    [self.navigationController.navigationBar addSubview:visualEffectView];
    self.navigationController.navigationBar.backgroundColor = [UIColor clearColor];
    [self.navigationController.navigationBar sendSubviewToBack:visualEffectView];

    // Here you can add visual effects to any UIView control.
    // Replace custom view with navigation bar in the above code to add effects to the custom view.
}

更新：

如果您发现在导航栏上添加模糊效果后，导航按钮不可见，请在添加模糊视图代码后添加以下行。

迅速：

self.navigationController?.navigationBar.sendSubview(toBack: visualEffectView)

目标 C：

[self.navigationController.navigationBar sendSubviewToBack:visualEffectView];

Answer 2

斯威夫特 4

extension UINavigationBar {
    func installBlurEffect() {
        isTranslucent = true
        setBackgroundImage(UIImage(), for: .default)
        let statusBarHeight: CGFloat = UIApplication.shared.statusBarFrame.height
        var blurFrame = bounds
        blurFrame.size.height += statusBarHeight
        blurFrame.origin.y -= statusBarHeight
        let blurView  = UIVisualEffectView(effect: UIBlurEffect(style: .light))
        blurView.isUserInteractionEnabled = false
        blurView.frame = blurFrame
        blurView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
        addSubview(blurView)
        blurView.layer.zPosition = -1
    }
}

用法

navigationController?.navigationBar.installBlurEffect()

Answer 3

注意：在iOS 11 上，函数sendSubviewToBack不能正常工作。 为了实现这一点，我们应该使用zPosition将模糊效果视图放置在其他视图下。

self.visualEffectView.layer.zPosition = -1;

Objective-C 代码

[self.navigationController.navigationBar setBackgroundImage:[UIImage new] forBarMetrics:UIBarMetricsDefault];
    self.navigationController.navigationBar.shadowImage = [UIImage new];
    self.navigationController.navigationBar.barTintColor = [UIColor whiteColor];
    self.navigationController.navigationBar.backgroundColor = [UIColor clearColor];
    self.navigationController.navigationBar.translucent = YES;
    // Add blur view
    CGRect bounds = self.navigationController.navigationBar.bounds;
    bounds.size.height += 20;
    bounds.origin.y -= 20;
    _visualEffectView = [[UIVisualEffectView alloc] initWithEffect:[UIBlurEffect effectWithStyle:UIBlurEffectStyleLight]];
    self.visualEffectView.frame = bounds;
    self.visualEffectView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
    self.visualEffectView.userInteractionEnabled = NO;
    self.visualEffectView.layer.zPosition = -1;
    [self.navigationController.navigationBar addSubview:self.visualEffectView];
    [self.navigationController.navigationBar sendSubviewToBack:self.visualEffectView];

斯威夫特 4 代码

  self.navigationController?.navigationBar.isTranslucent = true
    self.navigationController?.navigationBar.setBackgroundImage(UIImage(), for: .default)
    let visualEffectView   = UIVisualEffectView(effect: UIBlurEffect(style: .light))
    var bounds = view.bounds
    bounds.size.height += 20
    bounds.origin.y -= 20
    visualEffectView.isUserInteractionEnabled = false
    visualEffectView.frame = bounds
    visualEffectView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
    self.navigationController?.navigationBar.addSubview(visualEffectView)
    visualEffectView.layer.zPosition = -1

Answer 4

我已经添加了@Kampai的、 @Damasio的以及我的调整来解决我的问题（与pushNavigation相关）。代码将支持Swift 4.0+ 、 iOS9、Xcode 9

在您的 ViewController 的 ViewDidLoad() 中，只需调用

addBlurEffect(toView: self.navigationController?.navigationBar)

功能：

   //MARK :- It can be used in navBarGlassEffect view
func addBlurEffect(toView view:UIView?) {
    // Add blur view
    guard let view = view else { return }


    //This will let visualEffectView to work perfectly
    if let navBar = view as? UINavigationBar{
        navBar.setBackgroundImage(UIImage(), for: .default)
        navBar.shadowImage = UIImage()
    }


    var bounds = view.bounds
    bounds.offsetBy(dx: 0.0, dy: -20.0)
    bounds.size.height = bounds.height + 20.0


    let blurEffect = UIBlurEffect(style: .dark)
    let visualEffectView = UIVisualEffectView(effect: blurEffect)

    visualEffectView.isUserInteractionEnabled = false
    visualEffectView.frame = bounds
    visualEffectView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
    view.insertSubview(visualEffectView, at: 0)

}

Answer 5

如果在@Kampai 回答后您的状态栏没有生效，请添加以下内容：

bounds.offsetInPlace(dx: 0.0, dy: -20.0)
bounds.size.height = bounds.height + 20.0

本主题中解决的问题。

Answer 6

快速 3：

func addBlurEffect(toView view:UIView?) {
        // Add blur view
        guard let view = view else { return }

        //This will let visualEffectView to work perfectly
        if let navBar = view as? UINavigationBar{
            navBar.setBackgroundImage(UIImage(), for: .default)
            navBar.shadowImage = UIImage()
        }

        var bounds = view.bounds
        bounds.offsetBy(dx: 0.0, dy: -20.0)
        bounds.size.height = bounds.height + 20.0

        let blurEffect = UIBlurEffect(style: .dark)
        let visualEffectView = UIVisualEffectView(effect: blurEffect)

        visualEffectView.isUserInteractionEnabled = false
        visualEffectView.frame = bounds
        visualEffectView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
        view.insertSubview(visualEffectView, at: 0)

    }

Answer 7

斯威夫特 5、iOS 13 +

您可以在 AppDelegate 文件中使用UINavigationBarAppearance() 。 并且不要忘记为非滚动模式设置外观。 对我来说，它与 navigationBar.prefersLargeTitles 完美配合。

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
    let appearance = UINavigationBarAppearance()
    appearance.configureWithTransparentBackground()
    appearance.backgroundColor = UIColor.clear
    appearance.backgroundEffect = UIBlurEffect(style: .light) // or dark
    
    let scrollingAppearance = UINavigationBarAppearance()
    scrollingAppearance.configureWithTransparentBackground()
    scrollingAppearance.backgroundColor = .white // your view (superview) color
    
    UINavigationBar.appearance().standardAppearance = appearance
    UINavigationBar.appearance().scrollEdgeAppearance = scrollingAppearance
    UINavigationBar.appearance().compactAppearance = scrollingAppearance
    
    return true
}

Answer 8

我首先添加了 addBlurEffect() 方法，然后在 AppDelegate 中添加了

 UINavigationBar.appearance().setBackgroundImage(UIImage(), forBarMetrics: .Default)

 UINavigationBar.appearance().shadowImage = UIImage()

 UINavigationBar.appearance().backgroundColor = UIColor.clearColor()

 UINavigationBar.appearance().translucent = true

现在它对我有用

Answer 9

重点说明：在您实现上述代码以添加模糊视图后，1. 您需要将您的模糊视图发送回以显示其他内容 2. 您需要将您的模糊视图用户交互设置为 false 以便能够点击项目导航栏。

Answer 10

iOS NavigationBar 模糊效果

let navigationBar = self.navigationController?.navigationBar
if #available(iOS 13.0, *) {
    navigationBar?.standardAppearance.backgroundColor = .clear
    navigationBar?.standardAppearance.backgroundEffect = UIBlurEffect(style: .systemMaterial)
}

不要忘记将您的UITableView与 superview 对齐（非安全区域）

Answer 11

这是上面neoneye的解决方案，它完美地适用于UIToolbar。

extension UIToolbar {
    func toolBarBlurEffect() {
        isTranslucent = true
        setBackgroundImage(UIImage(), forToolbarPosition: .any, barMetrics: .default)
        let statusBarHeight: CGFloat = UIApplication.shared.statusBarFrame.height
        var blurFrame = bounds
        blurFrame.size.height += statusBarHeight
        let blurView  = UIVisualEffectView(effect: UIBlurEffect(style: .dark))
        blurView.isUserInteractionEnabled = false
        blurView.frame = blurFrame
        blurView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
        addSubview(blurView)
        blurView.layer.zPosition = -1
    }
}

用法类似：

navigationController?.toolbar.toolBarBlurEffect()