ios - 如何呈现 UICollectionViewController？

Question

我收到错误:

fatal error: unexpectedly found nil while unwrapping an Optional value

didTapUserScreenButton()不过工作正常，didTapChatControllerButton()给出错误。我认为它可能会出现错误，因为 didTapChatControllerButton()转到UiCollectionViewController?另一个工作正常，因为它会转到 UITableViewController? .

func didTapChatControllerButton() {
    let chat_log_controller = ChatLogController
    let navController = UINavigationController(rootViewController: chat_log_controller!)
    present(navController, animated: true, completion: nil)

}


func didTapUserScreenButton() {
    let user_screen_vc = usersScreenVC()
    let navController = UINavigationController(rootViewController: user_screen_vc)
    present(navController, animated: true, completion: nil)

Answer 1

您错过了(当前为空)初始化参数支架。尝试使用 tris:

let chat_log_controller = ChatLogController()
let navController = UINavigationController(rootViewController: chat_log_controller)
present(navController, animated: true, completion: nil)