SO中有许多答案可以提供隐藏导航栏阴影的解决方案 . 除了我在这里描述的这个特殊情况，这些对我有用 . 因此，这个问题不重复 .

为了测试这种特殊情况，我使用master-detail app模板创建了一个新项目 . 在DetailViewController - > viewDidAppear中，我编写了以下代码：

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

以上代码适用于Single View App和iPad Air 2模拟器 . 但是，它不适用于iPhoneX模拟器中的主从细节应用程序的detailViewController .

或者，我也尝试在viewDidAppear中检索navigationBar的子视图，并尝试隐藏阴影（请参阅下面的代码） . 但是，子视图计数为零 . 怎么会这样？

for parent in self.navigationController!.navigationBar.subviews {
        for childView in parent.subviews {
            if(childView is UIImageView) {
                childView.removeFromSuperview()
            }
        }
    }

对此有任何帮助非常感谢 .

Image of my storyboard

1 回答

对于通用流程

您可以使用此设置 . 假设 ViewController 是所有其他视图控制器类（您想要阴影的地方）， DetailViewController 是详细视图控制器类 .

我正在做的事情是保留阴影图像 .

ViewController.swift

class ViewController: UIViewController {

    var shadowImage: UIImage!

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

         shadowImage = self.navigationController?.navigationBar.shadowImage
    }


    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)

        self.navigationController?.navigationBar.shadowImage = shadowImage
    }

}

并且 DetailViewController.swift

class DetailViewController: UIViewController {


    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

        self.navigationController?.navigationBar.shadowImage = UIImage()
    }
}

Storyboard setup
enter image description here

Output

enter image description here

Note: 另一种巧妙的方法是将阴影存储在 DetailsViewController 中并在视图即将消失时进行设置

class DetailsViewController: UIViewController {

    var shadowImage: UIImage!

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

    }

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        shadowImage = self.navigationController?.navigationBar.shadowImage
        self.navigationController?.navigationBar.shadowImage = UIImage()
    }

    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        self.navigationController?.navigationBar.shadowImage = shadowImage
    }
}

这种解决方案更加优雅，可实现清洁管理 .

对于MasterDetailFlow，使用SplitViewController

在你的 MasterViewControlelr.swift

override func viewWillAppear(_ animated: Bool) {
    clearsSelectionOnViewWillAppear = splitViewController!.isCollapsed // placeholder code when you created the project
    super.viewWillAppear(animated)
    self.navigationController?.navigationBar.shadowImage = nil
}

override func viewWillDisappear(_ animated: Bool) {
    super.viewWillDisappear(animated)
    self.navigationController?.navigationBar.shadowImage = UIImage()
}

在你的 DetailViewController.swift

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)
    self.navigationController?.navigationBar.shadowImage = UIImage()
}

override func viewWillDisappear(_ animated: Bool) {
    super.viewWillDisappear(animated)
    self.navigationController?.navigationBar.shadowImage = nil
}

Output(Master/Detail flow)

enter image description here

回复于 2024-05-21T14:08:14+08:00

如何仅在详细视图中隐藏导航栏阴影？

1 回答

对于通用流程

对于MasterDetailFlow，使用SplitViewController

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