推送视图控制器在 Swift 中不起作用

Question

        let storyboard = UIStoryboard(name: "Main", bundle: nil)
        let playGameViewController = (storyboard.instantiateViewController(withIdentifier: "PlayGameViewController") as! PlayGameViewController)
        self.navigationController?.pushViewController(playGameViewController, animated: true)

push 不起作用，但我尝试了当前的工作，我想用 push 导航。

Answer 1

尝试运行以下代码以了解您哪里出错了。

let storyboard = UIStoryboard(name: "Main", bundle: nil)
guard let playGameViewController = storyboard.instantiateViewController(withIdentifier: "PlayGameViewController") as? PlayGameViewController else {
    print("This means you haven't set your view controller identifier properly.")
    return
}
guard let navigationController = navigationController else {
    print("This means you current view controller doesn't have a navigation controller")
    return
}
navigationController.pushViewController(playGameViewController, animated: true)

尝试使用断点来确定是否有任何变量为零。在您的情况下，您的 navigationController 为 nil 的可能性更大。