swift - 无法更改导航栏不透明度

Question

我正在尝试以下列方式设置我的应用程序的样式，但是我无法让我的导航栏达到这种不透明度级别

我使用以下代码来设置导航栏的样式:

unc application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
    UINavigationBar.appearance().barTintColor = UIColor(red: 1, green: 1, blue: 1, alpha: 0.1)
    UINavigationBar.appearance().tintColor = UIColor.whiteColor()
    UINavigationBar.appearance().titleTextAttributes = [NSForegroundColorAttributeName : UIColor.whiteColor()]
}

即使将 alpha 设置为 0.1，我仍然只能得到以下结果:

有没有可能实现这么低的不透明度？

Answer 1

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

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
}