C# using system.io not woking in my class but works in main

Question

I am working on an issue I do not remember ever having before. I am using VS2012 C#

When i add using System.IO; to my main program everything works fine

Answer 1

You haven't really given enough code to say for sure, but it sounds like you're probably trying to write "normal code" directly in a class declaration, instead of in a method or property declaration.

Classes can only include declarations - method declarations, field declarations etc. You can't write:

class Foo
{
    int i = 10; 
    Console.WriteLine(i);
}

etc. The first line is valid as it's a variable declaration - the second isn't, as it's just a method call. If you move the code into a method, then it's fine:

class Foo
{
    public void Bar()
    {
        int i = 10; 
        Console.WriteLine(i);
    }
}

Additionally, I'd suggest that you revisit your naming - using the same name for a class and a namespace is a bad idea.