問題描述
推送視圖控制器在 Swift 中不起作用 (Push view controller not working in Swift)
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let playGameViewController = (storyboard.instantiateViewController(withIdentifier: "PlayGameViewController") as! PlayGameViewController)
self.navigationController?.pushViewController(playGameViewController, animated: true)
push 沒用，但我嘗試過現在的工作，我想用 push 導航。
參考解法
方法 1:
Try running the below code to know where you have gone wrong.
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)
Try using breakpoints to figure out if any variable is nil. In your case, there is more probability for having your navigationController being nil.
(by Ashot Khachatryan、Frankenstein)