透明iOS导航栏

Question

我正在创建一个应用程序，我在互联网上浏览，我想知道他们是如何使这个透明的UINavigationBar像这样：

我在appdelegate中添加了以下内容：

UINavigationBar.appearance().translucent = true

但这只会让它看起来像：

如何使导航栏像第一个图像一样透明？

Answer 1

Swift 5仅适用于当前视图控制器

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

    // Make the navigation bar background clear
    navigationController?.navigationBar.setBackgroundImage(UIImage(), for: .default)
    navigationController?.navigationBar.shadowImage = UIImage()
    navigationController?.navigationBar.isTranslucent = true
}

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

    // Restore the navigation bar to default
    navigationController?.navigationBar.setBackgroundImage(nil, for: .default)
    navigationController?.navigationBar.shadowImage = nil
}

Answer 2

这是我找到的最好的方法。您可以将其粘贴到appDelegate的didFinishLaunchingWithOptions方法中：

斯威夫特3/4

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
    // Override point for customization after application launch.
    // Sets background to a blank/empty image
    UINavigationBar.appearance().setBackgroundImage(UIImage(), for: .default)
    // Sets shadow (line below the bar) to a blank image
    UINavigationBar.appearance().shadowImage = UIImage()
    // Sets the translucent background color
    UINavigationBar.appearance().backgroundColor = .clear
    // Set translucent. (Default value is already true, so this can be removed if desired.)
    UINavigationBar.appearance().isTranslucent = true
    return true
}

雨燕2.0

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
    // Override point for customization after application launch.
    // Sets background to a blank/empty image
    UINavigationBar.appearance().setBackgroundImage(UIImage(), forBarMetrics: .Default)
    // Sets shadow (line below the bar) to a blank image
    UINavigationBar.appearance().shadowImage = UIImage()
    // Sets the translucent background color
    UINavigationBar.appearance().backgroundColor = UIColor(red: 0.0, green: 0.0, blue: 0.0, alpha: 0.0)
    // Set translucent. (Default value is already true, so this can be removed if desired.)
    UINavigationBar.appearance().translucent = true

    return true
}

来源：在iOS 8.1中使导航栏对下图透明

Answer 3

您可以应用导航栏图像，如下所示为半透明。

目标C：

[self.navigationController.navigationBar setBackgroundImage:[UIImage new]
                     forBarMetrics:UIBarMetricsDefault]; //UIImageNamed:@"transparent.png"
self.navigationController.navigationBar.shadowImage = [UIImage new];////UIImageNamed:@"transparent.png"
self.navigationController.navigationBar.translucent = YES;
self.navigationController.view.backgroundColor = [UIColor clearColor];

Swift 3：

self.navigationController?.navigationBar.setBackgroundImage(UIImage(), for: .default) //UIImage.init(named: "transparent.png")
self.navigationController?.navigationBar.shadowImage = UIImage()
self.navigationController?.navigationBar.isTranslucent = true
self.navigationController?.view.backgroundColor = .clear