无法将 'UINavigationController' 类型的值转换为 'jacrs_ios.TopViewController'

Question

我是 Swift 的新手，我试图根据我正在学习的教程制作侧边菜单，但我运行遇到了这个错误。 "Could not cast value of type 'UINavigationController' (0x1026054a8) to 'jacrs_ios.TopViewController' (0x1009ac510)." 我注意到这里已经存在同样的问题，但我还是不明白。我将包括当前的情节提要，以防我做错了什么。谢谢

ViewController错误

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    let topViewController = segue.destination as! TopViewController
    topViewController.stringPassed = userName.text!
}

故事板

Answer 1

试试这个

if let navigationController = segue.destination as? UINavigationController
{

 let topViewController = navigationController?.topViewController as! TopViewController
 topViewController.stringPassed = userName.text!

}

无法将 'UINavigationController' 类型的值转换为 'jacrs_ios.TopViewController'

Could not cast value of type 'UINavigationController' to 'jacrs_ios.TopViewController'

uinavigationcontroller

ios

xcode-storyboard

swift