如何在 iOS 14 中自定义 MFMailComposeViewController

Question

我想在我的应用程序中自定义 MFMailComposeViewController 样式及其行为，但我所有的尝试都失败了。我尝试了几种方法： 第一种方式：

let mailComposeViewController = MFMailComposeViewController()
...
UINavigationBar.appearance().tintColor = UIColor.red //don't see changes
UINavigationBar.appearance().barTintColor = UIColor.green //don't see changes
UINavigationBar.appearance().backgroundColor = UIColor.yellow //don't see changes
UINavigationBar.appearance().isTranslucent = false //don't see changes
UINavigationBar.appearance().clipsToBounds = false //don't see changes
UINavigationBar.appearance().prefersLargeTitles = false //don't see changes

present(mailComposeViewController, animated: true, completion: nil)

第二种方式：

extension MFMailComposeViewController {
    open override func viewDidLoad() {
        super.viewDidLoad()
        self.navigationBar.clipsToBounds = true //don't see changes
        self.navigationBar.prefersLargeTitles = false //don't see changes
        self.navigationBar.isTranslucent = false //don't see changes
        self.navigationBar.barTintColor = UIColor.green //don't see changes
        self.navigationBar.tintColor = UIColor.red //only this works!
    }
}

PS 我最感兴趣的是将 prefersLargeTitles 更改为 false 或更改 navigationBarStyle 如下所示：

我的结果：

Answer 1

来自苹果：

重要 您不得修改此视图控制器呈现的视图层次结构。但是，您可以使用UIAppearance 协议自定义界面外观。

我认为 Apple 不同意您的第二种方式的代码，您不应该修改此视图。但是，请尝试：

UINavigationBar.appearance().tintColor = UIColor.red 
UINavigationBar.appearance().barTintColor = UIColor.green 
UINavigationBar.appearance().backgroundColor = UIColor.yellow 
UINavigationBar.appearance().isTranslucent = false 
UINavigationBar.appearance().clipsToBounds = false 
UINavigationBar.appearance().prefersLargeTitles = false 

let mailComposeViewController = MFMailComposeViewController()
present(mailComposeViewController, animated: true, completion: nil)