功能返回菜单选择;切换项目声明

Question

我必须创建一个函数来返回所选的菜单选项，然后使用switch语句来显示按下了哪个键，但是我在函数部分遇到了问题。

class Program
{   
    static void displayMainMenu()
    {
        string title = "Old Yeller Pet Store";
        Console.WriteLine("\n\n");
        Console.WriteLine(String.Format("{0," + ((Console.WindowWidth /2) + (title.Length / 2 )) + "}", title));
        Console.WriteLine("\n");

        title = "Main Menu";
        Console.WriteLine("\n\n");
        Console.WriteLine(String.Format("{0," + ((Console.WindowWidth /2) + (title.Length / 2 )) + "}", title));
        Console.WriteLine("\n");

        string line = "1.    Buy a Pet";
        Console.WriteLine(line.PadLeft(line.Length+1 + 50));

        string line2 = "2.    Buy Food";
        Console.WriteLine(line2.PadLeft(line2.Length+1 + 50));

        string line3 = "3.    File OPs";
        Console.WriteLine(line3.PadLeft(line3.Length+1 + 50));

        string line4 = "4.    Manager";
        Console.WriteLine(line4.PadLeft(line4.Length+1 + 50));

        string line5 = "5.    Quit";
        Console.WriteLine(line5.PadLeft(line5.Length+1 + 50));
    }

    static void getChoice()
    {
        Console.WriteLine("Please input which option you choose to use");
    }

    public static void Main(string[] args)
    {
        displayMainMenu();
        Console.ReadKey();
    }
}

}

Answer 1

你应该做的是修改getChoice方法以返回一个字符串，该字符串将是所选的选项。在getChoice方法中编写Console.ReadLine并将值放入变量并返回变量。这样你就可以在displayMenu之后调用函数getChoice并获取值。

我会自己提供代码但是因为这更像是一个功课，我认为你会更好地理解这个并尝试用这个想法自己做:)！

希望这可以帮助！

Answer 2

考虑一下Console.ReadKey（）将等到你按一个键继续。在你这样做之后，属性Console.ReadKey（）。Key将包含按下的键的值所以，在这种情况下......

var key = Console.ReadKey().Key;
switch (key) {
    case ConsoleKey.D1:
        Console.WriteLine("You pressed 1");
        break;
    case ConsoleKey.D2:
        Console.WriteLine("You pressed 2");
        break;
    //etc...//
    default:
        Console.WriteLine("You pressed something else");
        break;
}

Answer 3

所以我觉得这是进步，但我可能错了？ Switch语句会替换我的getChoice函数中的If语句吗？

class Program
{   
    static void displayMainMenu()
    {
        string title = "Old Yeller Pet Store";
        Console.WriteLine("\n\n");
        Console.WriteLine(String.Format("{0," + ((Console.WindowWidth /2) + (title.Length / 2 )) + "}", title));
        Console.WriteLine("\n");

        title = "Main Menu";
        Console.WriteLine("\n\n");
        Console.WriteLine(String.Format("{0," + ((Console.WindowWidth /2) + (title.Length / 2 )) + "}", title));
        Console.WriteLine("\n");

        string line = "1.    Buy a Pet";
        Console.WriteLine(line.PadLeft(line.Length+1 + 50));

        string line2 = "2.    Buy Food";
        Console.WriteLine(line2.PadLeft(line2.Length+1 + 50));

        string line3 = "3.    File OPs";
        Console.WriteLine(line3.PadLeft(line3.Length+1 + 50));

        string line4 = "4.    Manager";
        Console.WriteLine(line4.PadLeft(line4.Length+1 + 50));

        string line5 = "5.    Quit";
        Console.WriteLine(line5.PadLeft(line5.Length+1 + 50));


    }

    static void getChoice()
    {
        string option;
        int choice;
        Console.WriteLine("Please input which number option you choose to use");
        option = Console.ReadLine();
        choice = Convert.ToInt32(option);
        if (choice == 1)
        {
            Console.Write("Lipsum");
            //code to open Buy a Pet menu
        }



    }


    public static void Main(string[] args)
    {
        displayMainMenu ();
        getChoice();



        Console.ReadKey();

    }
}