Missing partial modifier on declaration of type 'Program'

Question

I started a project with the new console template that uses top level statements, but I wanted to add Program Main back in anyway.

However, when I add in the class like this:

// See https://aka.ms/new-console-template for more information
Console.WriteLine("Hello, World!");

public class Program
{
    public static void Main()
    {
        Console.WriteLine("Hello World");
    }
}

I get the error:

error CS0260: Missing partial modifier on declaration of type 'Program';
Another partial declaration of this type exists

Other stack overflow questions say to just add partial, but when I do that, I get the error:

warning CS7022: The entry point of the program is global code; 
ignoring 'Program.Main()' entry point

What's going on here?

score 1 · Answer 1 · answered Feb 24 '23 at 18:45

The problem was I forgot to remove the Console.WriteLine at the top as well.

Top level statements (added in C#9) will "compile down" into their own compiler generated Program class.

You can use sharplab to inspect the following code:

Console.WriteLine("Hello World");

Which will be compiled into something that looks like this:

[CompilerGenerated]
internal class Program
{
    private static void <Main>$(string[] args)
    {
        Console.WriteLine("Hello World");
    }
}

So you have to get rid of your top level statements if you want to use Program.Main (and vice versa).

There can only be one entry point

Missing partial modifier on declaration of type 'Program'

1 Answers1