使用 new UINavigationBarAppearance() API 在单个 ViewController 上设置 navigationBar 颜色？

Question

我需要为单个ViewController设置 NavigationBar 颜色。 我目前正在做的是在viewDidLoad()上设置导航颜色并将其重置为viewWillDissappear上的 .clear （因此它使用新推送的 VC 上设置的任何颜色）。 虽然这种排序有效，但速度不够快，因为直到推动 animation 结束才应用 .clear 颜色，导致导航栏颜色的可见半秒，直到它最终重置为 .clear。

当前代码如下所示：

override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        navigationController?.navigationBar.setNavBarColor(color: .red)
}

override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        navigationController?.navigationBar.setNavBarColor(color: .clear)
}


func setNavBarColor(color: UIColor) {
    let appearance: UINavigationBarAppearance = UINavigationBarAppearance()
    appearance.configureWithTransparentBackground()
    appearance.backgroundColor = color
    self.standardAppearance = appearance
    self.scrollEdgeAppearance = appearance
}

这可行但不够快，因为更改仅在推动 animation 结束后才会生效。 任何提示？

Answer 1

使用我的扩展程序设置您的导航栏：

extension UIViewController {
func configureNavigationBar(largeTitleColor: UIColor, backgoundColor: UIColor, tintColor: UIColor, title: String, preferredLargeTitle: Bool) {
if #available(iOS 13.0, *) {
let navBarAppearance = UINavigationBarAppearance()
navBarAppearance.configureWithOpaqueBackground()
navBarAppearance.largeTitleTextAttributes = [.foregroundColor: largeTitleColor]
navBarAppearance.titleTextAttributes = [.foregroundColor: largeTitleColor]
navBarAppearance.backgroundColor = backgoundColor
navigationController?.navigationBar.standardAppearance = navBarAppearance
navigationController?.navigationBar.compactAppearance = navBarAppearance
navigationController?.navigationBar.scrollEdgeAppearance = navBarAppearance

navigationController?.navigationBar.prefersLargeTitles = preferredLargeTitle
navigationController?.navigationBar.isTranslucent = false
navigationController?.navigationBar.tintColor = tintColor
navigationItem.title = title

} else {
// Fallback on earlier versions
navigationController?.navigationBar.barTintColor = backgoundColor
navigationController?.navigationBar.tintColor = tintColor
navigationController?.navigationBar.isTranslucent = false
navigationItem.title = title
  }
 }
}

在 viewWillAppear 或 viewDidLoad 中调用它并更改您的背景 colors，在您的情况下将背景设置为清除... 如何使用：

configureNavigationBar(largeTitleColor: .black, backgoundColor: .white, tintColor: .black, title: "yourTitle", preferredLargeTitle: true)

In your case, call configureNavigationBar func in viewWillAppear of start controller, call configureNavigationBar in viewDidLoad of destination controller.. ES: In SceneDelegate set your start controller under scene function:

func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
    guard let windowScene = (scene as? UIWindowScene) else { return }
    window = UIWindow(windowScene: windowScene)
    window?.makeKeyAndVisible()
    let controller = UINavigationController(rootViewController: StartController())
    window?.rootViewController = controller
    if #available(iOS 13, *) {
        window?.overrideUserInterfaceStyle = .dark
    }
}

这是开始控制器：

import UIKit

class StartController: UIViewController {

override func viewDidLoad() {
    super.viewDidLoad()
    
    view.backgroundColor = .white
    navigationItem.rightBarButtonItem = UIBarButtonItem(title: "GO", style: .plain, target: self, action: #selector(handleGo))
}

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)
    configureNavigationBar(largeTitleColor: .white, backgoundColor: .black, tintColor: .white, title: "Start", preferredLargeTitle: true)
}

@objc fileprivate func handleGo() {
    let controller = DestinationController()
    navigationController?.pushViewController(controller, animated: true)
 }
}

这是目的地控制器：

import UIKit

class DestinationController: UIViewController {

override func viewDidLoad() {
    super.viewDidLoad()
    
    view.backgroundColor = .white
    configureNavigationBar(largeTitleColor: .white, backgoundColor: .red, tintColor: .white, title: "Destination", preferredLargeTitle: true)
 }
}

结果：