Xcode无法更改View Controller

Question

let profileViewController = 
self.storyboard?.instantiateViewController(withIdentifier: 
"ProfileViewcontroller") as! ProfileViewController

self.navigationController?.pushViewController(profileViewController, 
animated: true)

http://prntscr.com/i87reg

不明白，为什么会这样。

Answer 1

您可以尝试初始化故事板吗？

故事板或navigationController都是零。

 let storyboard = UIStoryboard(name: "Main", Bundle: Bundle.main) 
 let profileViewController = storyboard.instantiateViewController(withIdentifier: "ProfileViewcontroller") as! ProfileViewController
 self.navigationController?.pushViewController(profileViewController, animated: true)