回到代码块的开头？

Question

在用户输入错误的键后，我需要返回此处显示的代码的开头。是否有任何简单的代码行会返回到另一行？如您所见，我已经设置了一个 if 语句，因此我可以添加一些可以返回到开头或代码中另一个区域的内容。我对 c# 和一般编程真的很陌生。我真的只是不想将所有代码再次输入到另一个会产生相同问题的 if 语句中。我希望在用户输入错误的密钥后再次运行代码，因为这样他们就可以重新读取它而无需从头开始。

//Runs battle interactive
Console.WriteLine("");
Console.WriteLine("You have encountered a simple guard!  He deals 2 damage per attack and has 1 HP.");
Console.WriteLine("You currently have: " + Program.Inventory);
Console.WriteLine("Choose a weapon!");
var input2 = Console.ReadKey();


//Key checker for items
switch (input2.Key)
{
    case ConsoleKey.D1:
        Console.WriteLine("");
        if (Items.iniFists == true)
        {
            Console.WriteLine("You have attacked with your Fists for 1 DMG!");
        }
        else
        {
            //this will never run, just a placeholder
            Console.WriteLine("You Don't have your fists!");
            switch (input2.Key)
            {
                case ConsoleKey.D1:
                    Console.WriteLine("");
                    if (Items.iniFists == true)
                    {
                        Console.WriteLine("You have attacked with your Fists for 1 DMG!");
                    }
                    else
                    {
                        //this will never run, just a placeholder
                        Console.WriteLine("You Don't have your fists!");
                    }
                    break;
                case ConsoleKey.D2:
                    Console.WriteLine("");
                    if (Items.iniLongsword == true)
                    {
                        Console.WriteLine("You have chosen to attack with the Longsword for 2 DMG!");
                    }
                    else
                    {
                        Console.WriteLine("You don't have a longsword!");
                    }
                    break;
                case ConsoleKey.D3:
                    Console.WriteLine("");
                    if (Items.iniBow == true)
                    {
                        Console.WriteLine("You have chosen to attack with the Bow for 3 DMG!");
                    }
                    else
                    {
                        Console.WriteLine("You don't have a Bow!");
                    }
                    break;
                case ConsoleKey.D4:
                    Console.WriteLine("");
                    if (Items.iniLightstaff == true)
                    {
                        Console.WriteLine("You have chosen to attack with the Lightstaff for 4 DMG!");
                    }
                    else
                    {
                        Console.WriteLine("You don't have a Lightstaff!");
                    }
                    break;
                case ConsoleKey.D5:
                    Console.WriteLine("");
                    Console.WriteLine("You can't attack with an Apple!");
                    break;
                case ConsoleKey.D6:
                    Console.WriteLine("");
                    Console.WriteLine("You can't attack with a Golden Key!");
                    break;
                case ConsoleKey.D7:
                    Console.WriteLine("");
                    Console.WriteLine("You can't attack with a Steak!");
                    break;
            }
        }
        break;
    case ConsoleKey.D2:
        Console.WriteLine("");
        if (Items.iniLongsword == true)
        {
            Console.WriteLine("You have chosen to attack with the Longsword for 2 DMG!");
        }
        else
        {
            Console.WriteLine("You don't have a longsword!");
        }
        break;
    case ConsoleKey.D3:
        Console.WriteLine("");
        if (Items.iniBow == true)
        {
            Console.WriteLine("You have chosen to attack with the Bow for 3 DMG!");
        }
        else
        {
            Console.WriteLine("You don't have a Bow!");
        }
        break;
    case ConsoleKey.D4:
        Console.WriteLine("");
        if (Items.iniLightstaff == true)
        {
            Console.WriteLine("You have chosen to attack with the Lightstaff for 4 DMG!");
        }
        else
        {
            Console.WriteLine("You don't have a Lightstaff!");
        }
        break;
    case ConsoleKey.D5:
        Console.WriteLine("");
        Console.WriteLine("You can't attack with an Apple!");
        break;
    case ConsoleKey.D6:
        Console.WriteLine("");
        Console.WriteLine("You can't attack with a Golden Key!");
        break;
    case ConsoleKey.D7:
        Console.WriteLine("");
        Console.WriteLine("You can't attack with a Steak!");
        break;
}

Answer 1

C# 支持代码中的标签，但不建议这样做，因为它违反了许多编码最佳实践，但我想任何规则总有例外。

class Program
{
    static void Main(string[] args)
    {
    Start:
        Console.WriteLine("Start Here... Press any key");
        var key = Console.ReadKey(true);

        switch (key.Key)
        {
            case ConsoleKey.A:
                goto MyLabel;

            case ConsoleKey.B:
                goto MyLabel2;

            case ConsoleKey.C:
                goto MyLabel3;

            default:
                Console.WriteLine("Bad Choice");
                goto Start;

        }

    MyLabel:
        Console.WriteLine("MyLabel: A");
        goto Start;

    MyLabel2:
        Console.WriteLine("MyLabel: B");
        goto Start;


    MyLabel3:
        Console.WriteLine("MyLabel: C");
        goto Start;
    }
}

您可以在此处找到更多信息：

http://msdn.microsoft.com/en-us/library/d96yfwee.aspx http://msdn.microsoft.com/en-us/library/13940fs2.aspx

Answer 2

你有几个选择，你可以使用 while 循环

bool continue = true;
while(continue == true)// or you can simply type "while(continue)"
{
    /* everything inside the `while` loop will be 
       repeated until `continue` is not `true`. */
}

你也可以使用方法

public static void doStuff()
{
    // insert stuff here
}

然后你就可以在课堂上的其他地方调用它

if(x = 6)
{
    doStuff();  //this line does the stuff
    doStuff();  // this line does the stuff again.
}

Answer 3

对此的一个答案是检查您在这样的循环中是否有有效输入：

while (true)
{
    ConsoleKey i = Console.ReadKey()
    if (i == ConsoleKey.D1 || ... ) //Check if it's equal to any valid key, you 
                                    //might be able to simplify it with <= and 
                                    //>= if valid keys are sequential.
        break;
    Console.WriteLine("You have entered an invalid key");
}

或者，您可以在 switch 块的末尾添加 goto 语句：

SwitchStatement: switch(input2.Key)
...
default:
    Console.WriteLine("Invalid key pressed");

    goto SwitchStatement;
    break;

}