无法更改导航栏颜色

Question

我试图在包含UISearchController的视图中更改导航栏的颜色.我以前在appDelegate中为整个应用程序设置了导航栏的颜色,但我希望这个视图导航栏有不同的颜色.问题是,我不知道放置代码的功能,以便它将覆盖appDelegate代码.例如,viewDidLoad和viewWilAppear在视图首次加载时不会更改颜色,只有在我输入和取消searchController之后.我应该放置以下哪个功能？

UINavigationBar.appearance().backgroundColor = UIColor(red: 0, green: 0, blue: 0, alpha: 1)

Answer 1

有两种方法可以做到这一点.您可以修改在AppDelegate中为整个应用程序设置的外观代理,也可以修改特定屏幕的单个导航栏.

当您关闭视图时 - 需要重置viewWillDisappear中的barTintColor.

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

    // Set to new colour for whole app
    UINavigationBar.appearance().barTintColor = UIColor.blueColor()

    // Or, Set to new colour for just this navigation bar
    self.navigationController?.navigationBar.barTintColor = UIColor.blueColor()
}

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

    //Revert to old colour, whole app
    UINavigationBar.appearance().barTintColor = UIColor.redColor()

    //Revert to old colour, just this navigation bar
    self.navigationController?.navigationBar.barTintColor = UIColor.redColor()
}