Question

我有一个主菜单，要求用户输入一个数字，对于每个数字，在switch语句中都有一个case 我想要做的是，当用户输入一个没有大小写的数字时，它应该再次返回相同的菜单

所以我创建了一个包含switch语句的函数，它的默认值是函数本身，但它不起作用（不再显示该函数）我该怎么办？

static void AdminMenu()
{
    char innerchoice;
    Console.WriteLine("Press [1] to Add new student.");
    Console.WriteLine("Press [2] to Add new course.");
    Console.WriteLine("Press [3] to Enter course prerequisite.");
    Console.WriteLine("Press [4] to View List of all students in a specific course.");
    Console.WriteLine("Press [5] to View List of Finished courses.");
    Console.WriteLine("Press [6] to View List of courses in progress.");
    Console.WriteLine("Press [7] to edit all course data.");
    innerchoice = char.Parse(Console.ReadLine());

    switch (innerchoice)
    {
        case '1':    
            break;

        case '2':    
            break;

        case '3':      
            break;

        case '4':       
            break;

        case '5':    
            break;

        case '6':       
            break;

        case '7':    
            break;

        default:
            AdminMenu();


    }
}

Answer 1

不要使用递归来实现用户菜单。它会使您的代码变得混乱且难以调试。只需使用任何循环并检查它是否应该再次运行：

void PrintMenu()
{
    Console.WriteLine("Press [1] to Add new student.");
    Console.WriteLine("Press [2] to Add new course.");
    Console.WriteLine("Press [3] to Enter course prerequisite.");
    Console.WriteLine("Press [4] to View List of all students in a specific course.");
    Console.WriteLine("Press [5] to View List of Finished courses.");
    Console.WriteLine("Press [6] to View List of courses in progress.");
    Console.WriteLine("Press [7] to edit all course data.");
}

static void AdminMenu()
{
    bool run = true;
    while(run)
    {
        PrintMenu();
        char innerchoice = char.Parse(Console.ReadLine());

        switch (innerchoice)
        {
            case '1':
                run = false;
                break;
            case '2':    
                run = false;
                break;
            case '3':      
                run = false;
                break;
            case '4':       
                run = false;
                break;
            case '5':    
                run = false;
                break;
            case '6':       
                run = false;
                break;
            case '7':    
                run = false;
                break;
        }
    }
}

Answer 2

我为你的默认情况添加了一个休息时间，它对我有用

您的默认情况应该是

default:
     AdminMenu();
     break;

Answer 3

您必须在默认情况下添加break，否则会出错。

试用此代码：

static void AdminMenu()
{
char innerchoice;
Console.WriteLine("Press [1] to Add new student.");
Console.WriteLine("Press [2] to Add new course.");
Console.WriteLine("Press [3] to Enter course prerequisite.");
Console.WriteLine("Press [4] to View List of all students in a specific course.");
Console.WriteLine("Press [5] to View List of Finished courses.");
Console.WriteLine("Press [6] to View List of courses in progress.");
Console.WriteLine("Press [7] to edit all course data.");
innerchoice = char.Parse(Console.ReadLine());

switch (innerchoice)
{
    case '1':    
        break;

    case '2':    
        break;

    case '3':      
        break;

    case '4':       
        break;

    case '5':    
        break;

    case '6':       
        break;

    case '7':    
        break;

    default:
        AdminMenu();
        break;// add break in default

}
}

输出

Answer 4

您可以使用bool来控制值是否有效并将其置于循环

试用此代码：

    static void AdminMenu()
    {
        char innerchoice;
        bool Leave = false;
        while (Leave == false)
        {
            Leave = true;
            innerchoice = GetChoice();
            switch (innerchoice)
            {
                case '1':
                    break;
                case '2':
                    break;
                case '3':
                    break;
                case '4':
                    break;
                case '5':
                    break;
                case '6':
                    break;
                case '7':
                    break;
                default:
                    Leave = false;
                    Console.Clear();
                    Console.WriteLine("Press a valid value.");
                    break;
            }
        }
    }

    static char GetChoice()
    {
        Console.WriteLine("Press [1] to Add new student.");
        Console.WriteLine("Press [2] to Add new course.");
        Console.WriteLine("Press [3] to Enter course prerequisite.");
        Console.WriteLine("Press [4] to View List of all students in a specific course.");
        Console.WriteLine("Press [5] to View List of Finished courses.");
        Console.WriteLine("Press [6] to View List of courses in progress.");
        Console.WriteLine("Press [7] to edit all course data.");

        return char.Parse(Console.ReadLine());
    }

这是按下无效值时所做的output。

如何从交换机调用方法？

4 个答案: