如何在 C# 中使用参数调用 Main 中的方法？

Question

I have 'StudentNum' declared as an int in my StudentNumber method in the parameter list, but the program keeps telling me it does not exist in the current context. Does anybody know why? Sorry I am very new to C# and in a past C++ class when we called functions I remember jus doing something like: StudentNumber(StudentNum). When I remove StudentNum from the parameter list, the program then says "No overload for method 'StudentNumber' takes 0 arguments. I want the program to prompt the user for a number, and if it is less than 20 then they get the message saying so. Thanks! Here's my code:

namespace RegisterStudent
{
  public class Program
  {
    static void Main(string[] args)
    {
      Console.WriteLine("Hi. Please Enter The Student Number Then Press Enter");
      Console.ReadLine();
      StudentNumber();
    }

    public static void StudentNumber(int StudentNum)
    {

      if (StudentNum > 20)
      {
        Console.WriteLine("Sorry, the class is full.");
        Console.ReadLine();
      }
      else
      {
        Console.WriteLine("You are now enrolled in the course");
        Console.ReadLine();
      }

    }

    public static void StudentHours()
    {

    }
    public static void Conflict()
    {

    }
  }
}

Answer 1

Change your lines

Console.ReadLine();
StudentNumber();

as

StudentNumber(int.Parse(Console.ReadLine()));

Answer 2

your problem that you arent passing any argument to your function StudentNumber(int StudentNum) the error tell you that there is no any overloaded function that has no argument so you should pass int paramater to StudentNumber() to work correctly

Console.ReadLine(); read string line so it should be converted to int by one of these methods:

Int.Parse()

Convert.ToInt()

Int.TryParse()

here the correct version of the code :

static void Main(string[] args)
    {
      int stdnum;
      Console.WriteLine("Hi. Please Enter The Student Number Then Press Enter");
      stdnum=Convert.ToInt32(Console.ReadLine());
      StudentNumber(stdnum);
    }

or instead you can use :

stdnum=Int32.Parse(Console.ReadLine());

I think that clarify your problem now.