如何在我的UINavigationBar后面获得模糊效果

Question

我一直试图让我的scrollView出现在navigationBar下稍微模糊，就像苹果消息应用中的情况一样。我尝试了以下方法，但没有一种方法有效：

1：

self.navigationController?.navigationBar.isTranslucent = true

2：

self.navigationController?.navigationBar.barStyle = UIBarStyle.blackTranslucent

3：

self.navigationController?.navigationBar.setBackgroundImage(UIImage(), for: UIBarMetrics.default)

4：

self.navigationController?.navigationBar.backgroundColor = UIColor.clear()

我已经阅读了许多上述方法变化的帖子，并尝试了大部分但无济于事。我认为设置isTranslucent = true的目的是获得完全相同的效果。还有什么我应该尝试的吗？基本上我只是想让我的导航栏略微透视。

Answer 1

UIVisualEffectView正是您所寻找的，并且经过充分展示here：

let bounds = self.navigationController?.navigationBar.bounds as CGRect!
let visualEffectView = UIVisualEffectView(effect: UIBlurEffect(style: .Light))
visualEffectView.frame = bounds
self.navigationController?.navigationBar.addSubview(visualEffectView)

那就是说，使用你的方法1和2也应该有效：

self.navigationController.navigationBar.translucent = YES;
self.navigationController.navigationBar.topItem.title = @"Contacts";
self.navigationController.navigationBar.barStyle = UIBarStyleBlack;

Answer 2

    let blurEffect = UIBlurEffect(style: UIBlurEffectStyle.Dark)
    let blurEffectView = UIVisualEffectView(effect: blurEffect)
    blurEffectView.frame = (self.navigationController?.navigationBar.bounds)!
    self.navigationController?.navigationBar.addSubview(blurEffectView)

Answer 3

在这里，您可以为导航栏模糊效果添加此代码，此功能非常适合您

func navigationBlurEffect() {
    // Add blur view
    let bounds = self.navigationController?.navigationBar.bounds as CGRect!
    let visualEffectView = UIVisualEffectView(effect: UIBlurEffect(style: .Light))
    visualEffectView.frame = bounds
    visualEffectView.autoresizingMask = [.FlexibleWidth, .FlexibleHeight]

    //here you can choose one 
    self.navigationController?.navigationBar.addSubview(visualEffectView)
    // Or
    /*
 If you find that after adding blur effect on navigationBar, navigation buttons are not visible then add below line after adding blurView code.
    */ 
    self.navigationController?.navigationBar.sendSubviewToBack(visualEffectView)

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

// **这仅适用于Image Blur代码 此代码可用于图像模糊效果

  func getImageBlur(image:UIImageView){
        let blurEffect = UIBlurEffect(style: UIBlurEffectStyle.Light)
        let blurEffectView = UIVisualEffectView(effect: blurEffect)
        blurEffectView.frame = (image.bounds)
        blurEffectView.autoresizingMask = [.FlexibleWidth, .FlexibleHeight]
        image.addSubview(blurEffectView)
    }