如何在C＃中定义全局结构？

Question

I want to define a global structure in C# and use it in three separate subroutines. I have already created the structure but I don't know how to make it a global variable so I can use it in multiple sections of my code. Any help is appreciated.

    public struct Simple
    {
        public int Position;
        public bool Exists;
        public double LastValue;
    };


    static void Main(string[] args)
    {
        Simple s;
        s.Position = 1;
        s.Exists = false;
        s.LastValue = 5.5;
    }

So I want to use a Simple structure in two other routines in my code and possible pass it to different form (multiple usage of one variable).

Answer 1

The closest thing to "global" in C# is "static". Simply define the class and all members as static and it'll be accessible from anywhere the containing namespace is referenced. EDIT as Servy correctly points out, the class itself does not have to be static; however doing so forces all members to be static at compile-time. Also, static members can have any visibility, so you can have a private static field used by a public static property or method, and you can have an internal static class that won't be visible outside its home assembly. Just being static doesn't automatically make it wide open.

However, a better pattern might be the Singleton; you define a class that has one static instance of itself, that can then be passed around. The benefit is that you can still deal with the object as an instance class if you want to, but the same instance is available everywhere using a static getter. Here's some reading material: http://csharpindepth.com/Articles/General/Singleton.aspx

Answer 2

In your case it appears that you have a object as a local variable in your main method that you need to use in another method. The appropriate solution in this context is to add a parameter to that other method. Take a look at this example:

public class MyObject
{
    public int Value;
}

public static void Main(string[] args)
{
    MyObject obj = new MyObject();

    obj.Value = 42;

    PrintObject(obj);

    Console.WriteLine("Press any key to exit...");
    Console.ReadKey(true);
}

public static void PrintObject(MyObject obj)
{
    Console.WriteLine(obj.Value);
}