ios - 基于时间的问候应用程序无法正常工作， swift

Question

所以我正在尝试快速制作一个简单的基于时间的问候应用程序，但它不起作用，当我在我的应用程序的文本字段中按回车键时，它只是卡住，Xcode 将我带到 AppDelegate并且有一行上面有一个小标记，我不知道出了什么问题，为什么。

Xcode 说我的代码在编辑时没有错误，但应用程序无法运行。这是我的代码:

import UIKit

class ViewController: UIViewController {

    @IBOutlet weak var nameLabel: UILabel!

    override func viewDidLoad() {
        super.viewDidLoad()
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }

    @IBAction func nameTextField(nameTextField: UITextField) {
        var currentTimeOfDay = ""

        let hour = NSCalendar.current.component(.hour, from: NSDate() as Date)
        if hour >= 0 && hour < 12 {

            currentTimeOfDay = "Morning"

        } else if hour >= 12 && hour < 17 {

            currentTimeOfDay = "Afternoon"

        } else if hour >= 17 {

            currentTimeOfDay = "Evening"

        }

        nameLabel.text = "Good \(currentTimeOfDay) \(nameTextField)"       
    }  
}

感谢任何帮助!

编辑:我不再需要答案，因为我只是在玩 Swift。无论如何，还是要感谢所有回答或评论的人!

-驼鹿

Answer 1

这是我的完整工作应用。

import UIKit

class ViewController: UIViewController {

    @IBOutlet weak var helloLbl: UILabel!
    @IBOutlet weak var nameText: UITextField!

    var heyName = "Hey"
    var greeting = ""


    func greetingLogic() {
        let date = NSDate()
        let calendar = NSCalendar.current
        let currentHour = calendar.component(.hour, from: date as Date)
        let hourInt = Int(currentHour.description)!

        if hourInt >= 12 && hourInt <= 16 {
            greeting = "Good Afternoon"
        }
        else if hourInt >= 7 && hourInt <= 12 {
            greeting = "Good Morning"
        }
        else if hourInt >= 16 && hourInt <= 20 {
            greeting = "Good Evening"
        }
        else if hourInt >= 20 && hourInt <= 24 {
            greeting = "Good Night"
        }
        else if hourInt >= 0 && hourInt <= 7 {
            greeting = "You should be sleeping right now"
        }

        helloLbl.text = greeting
    }

    override func viewDidLoad() {
        super.viewDidLoad()

        greetingLogic()

    }


    @IBAction func sayHello(_ sender: UIButton) {

        helloLbl.text = greeting + ", " + nameText.text!.capitalized + "!"

    }

}