SO中有许多答案,它们提供了隐藏导航栏阴影的解决方案。这些对我有用,除了这种情况下,我将在这里描述。因此,这个问题不是重复的。
为了测试这种特殊情况,我使用主从应用程序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应用程序和iPad Air 2模拟器。但是,它不适用于iPhoneX模拟器中的主从应用程序的detailViewController。
或者,我也尝试在viewDidAppear中检索navigationBar的子视图,并尝试隐藏阴影(请参见下面的代码)。但是,子视图计数为零。怎么可能呢?
for parent in self.navigationController!.navigationBar.subviews {
for childView in parent.subviews {
if(childView is UIImageView) {
childView.removeFromSuperview()
}
}
}
在此方面的任何帮助都将受到赞赏。
答案 0 :(得分:1)
您可以使用此设置。说ViewController
是所有其他视图控制器类(需要阴影的地方),而DetailViewController
是详细信息视图控制器类。
我正在做的是保存阴影图像的事情。
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
}
}
和 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()
}
}
输出
注意: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
}
}
此解决方案更加优雅,可带来整洁的管理。
在您的 MasterViewControlelr.swift
中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()
}
在您的 DetailViewController.swift
中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
}
输出(主/明细流)