使用 Swift 在 AppDelegate 中设置 UINavigationBar setBackgroundImage [英] UINavigationBar setBackgroundImage in AppDelegate with Swift

问题描述

我正在尝试在 Swift 的 App Delegate 中全局设置导航栏的背景图像.我可以让它在这样的单个视图控制器上工作:

I am trying to set a background image to the navigation bar globally in the App Delegate in Swift. I can get it to work on an individual View Controller like this:

var topBar: UINavigationBar!

topBar.setBackgroundImage(UIImage(named: "navbar"), forBarMetrics:
.Default)

但是当我尝试将以下内容添加到 App Delegate 时，它​​会因未捕获的异常而崩溃:

But when I try and add the following to the App Delegate, it crashes with an uncaught exception:

UINavigationBar.appearance().setBackgroundImage(UIImage(named:
"navbar"), forBarMetrics: .Default)

推荐答案

好的，我删除了导航栏并在情节提要中添加了新的导航栏……现在它只适用于 App Delegate 代码.我猜这只是 Xcode 6/Swift 出了问题.

OK, I deleted the navigation bars and added new ones in the storyboard... now it works with just the App Delegate code. It's just Xcode 6/Swift being buggy, I guess.

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