Golang compiled into DLL file

Golang needs gcc to compile the dll, so install MinGW first.

Windows 64-bit systems should download the 64-bit version of MinGW:  https://sourceforge.net/projects/mingw-w64/

After downloading, run mingw-w64-install.exe to complete the MingGW installation.

 

Write the golang program exportgo.go:

package main

import "C"
import "fmt"

//export PrintBye
func PrintBye() {
    fmt.Println("From DLL: Bye!")
}

//export Sum
func Sum(a int, b int) int {
    return a + b;
}

func main() {
    // Need a main function to make CGO compile package as C shared library
}

Compile into a DLL file:

go build -buildmode=c-shared -o exportgo.dll exportgo.go

After compiling, exportgo.dll and exportgo.h are obtained.

 

Referring to the function definitions in the exportgo.h file, write the C# file importgo.cs:

using System;
using System.Runtime.InteropServices;

namespace HelloWorld
{
    class Hello 
    {
        [DllImport("exportgo.dll", EntryPoint="PrintBye")]
        static extern void PrintBye();

        [DllImport("exportgo.dll", EntryPoint="Sum")]
        static extern int Sum(int a, int b);

        static void Main() 
        {
            Console.WriteLine("Hello World!");
            PrintBye();

            Console.WriteLine(Sum(33, 22));
        }
    }
}

Compile CS file to get exe

csc importgo.cs

Put the exe and dll in the same directory and run it.

>importgo.exe

Hello World!
From DLL: Bye!
55

Replenish:

String parameters in golang can be referenced in C# as follows:

    public struct GoString
    {
        public string Value { get; set; }
        public int Length { get; set; }

        public static implicit operator GoString(string s)
        {
            return new GoString() { Value = s, Length = s.Length };
        }

        public static implicit operator string(GoString s) => s.Value;
    }