ios Swift 中的透明 UINavigationBar

Transparent UINavigationBar in Swift

提问by Nikita Zernov

I am trying to make my UINavigationBarin UINavigationControllertransparent. I created a subclass of UINavigationControllerand liked it to a scene in my storyboard file. Here's a piece of my subclass:

我正在努力使我UINavigationBar的信息UINavigationController透明。我创建了一个子类，UINavigationController并喜欢它在我的故事板文件中的一个场景中。这是我的子类的一部分：

override func viewDidLoad() {
    super.viewDidLoad()

    // Do any additional setup after loading the view.
    let size = self.navigationBar.frame.size
    self.navigationBar.setBackgroundImage(imageWithColor(UIColor.blackColor(), size: size, alpha: 0.2), forBarMetrics: UIBarMetrics.Default)
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

func imageWithColor(color: UIColor, size: CGSize, alpha: CGFloat) -> UIImage {
    UIGraphicsBeginImageContext(size)
    let currentContext = UIGraphicsGetCurrentContext()
    let fillRect = CGRectMake(0, 0, size.width, size.height)
    CGContextSetFillColorWithColor(currentContext, color.CGColor)
    CGContextSetAlpha(currentContext, alpha)
    CGContextFillRect(currentContext, fillRect)
    let retval: UIImage = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()
    return retval
}

When I run my application a have a navigation bar transparent, but status bar is just black.

当我运行我的应用程序时，导航栏是透明的，但状态栏是黑色的。

For example if I do such thing on UITabBar- it works.

例如，如果我做这样的事情UITabBar- 它有效。

回答by Ashish Kakkad

Hope it help you

希望对你有帮助

Swift 2:

斯威夫特 2：

self.navigationController.navigationBar.setBackgroundImage(UIImage(), forBarMetrics: UIBarMetrics.Default)
self.navigationController.navigationBar.shadowImage = UIImage()
self.navigationController.navigationBar.isTranslucent = true
self.navigationController.view.backgroundColor = UIColor.clearColor()

Swift 4.2to Swift 5.1

Swift 4.2到Swift 5.1

self.navigationController?.navigationBar.setBackgroundImage(UIImage(), for: UIBarMetrics.default)
self.navigationController?.navigationBar.shadowImage = UIImage()
self.navigationController?.navigationBar.isTranslucent = true
self.navigationController?.view.backgroundColor = UIColor.clear

Or If you want to sublcass the navigation controller then refer this answer.

或者，如果您想转用导航控制器，请参考此答案。

---

---

Change the status bar style via :

通过以下方式更改状态栏样式：

In your Info.plist you need to define View controller-based status bar appearanceto any value.

在您的 Info.plist 中，您需要将基于视图控制器的状态栏外观定义为任何值。

UIApplication.shared.statusBarStyle = .lightContent

If you want to hide the status bar:

如果要隐藏状态栏：

UIApplication.shared.isStatusBarHidden = true

Getting this output by light content and by transparent navigation. I have view background is gray. you can see the transparency.

通过轻量内容和透明导航获取此输出。我有视图背景是灰色的。你可以看到透明度。

iPhone XR - Swift 4.2 - Large Titles (Test Screenshot)

iPhone XR - Swift 4.2 - 大标题（测试截图）

回答by Chamath Jeevan

If you're using Swift 2.0 uses the code block below:

如果您使用的是 Swift 2.0，请使用以下代码块：

 self.navigationController?.navigationBar.setBackgroundImage(UIImage(), forBarMetrics: UIBarMetrics.Default)
 self.navigationController?.navigationBar.shadowImage = UIImage()
 self.navigationController?.navigationBar.translucent = true

For Swift 3.0 use:

对于 Swift 3.0 使用：

navigationController?.setNavigationBarHidden(false, animated: true)
navigationController?.navigationBar.setBackgroundImage(UIImage(), for: UIBarMetrics.default)
navigationController?.navigationBar.shadowImage = UIImage()
navigationController?.navigationBar.isTranslucent = true

回答by user550088

Create an extension of UINavigationControllerand present or hide transparent navigation bar.

创建扩展UINavigationController并显示或隐藏透明导航栏。

extension UINavigationController {

    public func presentTransparentNavigationBar() {
        navigationBar.setBackgroundImage(UIImage(), for:UIBarMetrics.default)
        navigationBar.isTranslucent = true
        navigationBar.shadowImage = UIImage()
        setNavigationBarHidden(false, animated:true)
    }

    public func hideTransparentNavigationBar() {
        setNavigationBarHidden(true, animated:false)
        navigationBar.setBackgroundImage(UINavigationBar.appearance().backgroundImage(for: UIBarMetrics.default), for:UIBarMetrics.default)
        navigationBar.isTranslucent = UINavigationBar.appearance().isTranslucent
        navigationBar.shadowImage = UINavigationBar.appearance().shadowImage
    }
}

回答by Jeff Gu Kang

Swift 3.0.1 with Xcode 8.1

Swift 3.0.1 与 Xcode 8.1

In your UINavigationController

在你的 UINavigationController

override func viewDidLoad() {
    super.viewDidLoad()
    self.navigationBar.setBackgroundImage(UIImage(), for: UIBarMetrics.default)
    self.navigationBar.shadowImage = UIImage()
    self.navigationBar.isTranslucent = true
    self.view.backgroundColor = UIColor.clear
}

回答by Ankit Kumar Gupta

Xcode 8.x : Swift 3: Extension for the same Write once use throughout

Xcode 8.x : Swift 3: 对同一个 Write 的扩展贯穿始终

extension UINavigationBar {

    func transparentNavigationBar() {
        self.setBackgroundImage(UIImage(), for: .default)
        self.shadowImage = UIImage()
        self.isTranslucent = true
    }
} 

回答by Alexander Stepanishin

I tried all methods above and still got white space instead of content that supposed to be rendered through. If you want to draw regular subview (Google map f.e.), not UIScrollView content through navigation bar, then you need to set subview's frame in viewDidAppear. So step 1:

我尝试了上面的所有方法，但仍然得到空白而不是应该渲染的内容。如果你想通过导航栏绘制常规子视图（谷歌地图fe），而不是 UIScrollView 内容，那么你需要在viewDidAppear. 所以第一步：

existingNavigationBar.setBackgroundImage(transparentImageFromAssets, for: .default)
existingNavigationBar.shadowImage = transparentImageFromAssets
existingNavigationBar.isTranslucent = true

step 2:

第2步：

override func viewDidAppear(_ animated: Bool) {
      super.viewDidAppear(animated)
      self.mapView.frame = UIScreen.main.bounds
  }

This worked for me.

这对我有用。