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tzainten

•Created by tzainten on 1/4/2023 in #help

❔ Confused about Assembly.Load (Hotloading CSharp Assemblies)

I want to be able to load/unload user made C# libraries during runtime. However, these user libraries rely on one C# FunctionLibrary.dll file I made that will basically hold functions that call Native C++ functions. FunctionLibrary.dll is structured like this:

C#
namespace FunctionLibrary;

public static class Module
{
    public static bool Test = false;
}

C#
namespace FunctionLibrary;

public static class Module
{
    public static bool Test = false;
}

UserLibrary.dll is structured like this:

C#
using FunctionLibrary;

public class MyLibrary
{
    public static void OnStartup()
    {
        Console.WriteLine(FunctionLibrary.Test);
    }
}

C#
using FunctionLibrary;

public class MyLibrary
{
    public static void OnStartup()
    {
        Console.WriteLine(FunctionLibrary.Test);
    }
}

FunctionLibrary.dll and UserLibrary.dll are loaded using Assembly.Load, which looks something like this:

C#
public unsafe class Program
{
    [UnmanagedCallersOnly]
    public static void Main()
    {
        try
        {
            Assembly funcLibrary = Assembly.Load(ToMemoryStream(File.OpenRead("FunctionLibrary.dll")));
            Type? module = funcLibrary.GetType("FunctionLibrary.Module");
            FieldInfo testField = module?.GetField("Test", BindingFlags.Static | BindingFlags.Public);
            testField.SetValue(null, true); // Set FunctionLibrary.Module.Test = true

            Assembly userLibrary = Assembly.Load(ToMemoryStream(File.OpenRead("UserLibrary.dll")));
            Type? userModule = userLibrary.GetType("MyLibrary.MyModule");
            MethodInfo entryPoint = userModule?.GetMethod("OnStartup", BindingFlags.Static | BindingFlags.Public);
            entryPoint.Invoke(null, null); // Print out the value of FunctionLibrary.Module.Test, expected to == true
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex);
        }
    }
}

C#
public unsafe class Program
{
    [UnmanagedCallersOnly]
    public static void Main()
    {
        try
        {
            Assembly funcLibrary = Assembly.Load(ToMemoryStream(File.OpenRead("FunctionLibrary.dll")));
            Type? module = funcLibrary.GetType("FunctionLibrary.Module");
            FieldInfo testField = module?.GetField("Test", BindingFlags.Static | BindingFlags.Public);
            testField.SetValue(null, true); // Set FunctionLibrary.Module.Test = true

            Assembly userLibrary = Assembly.Load(ToMemoryStream(File.OpenRead("UserLibrary.dll")));
            Type? userModule = userLibrary.GetType("MyLibrary.MyModule");
            MethodInfo entryPoint = userModule?.GetMethod("OnStartup", BindingFlags.Static | BindingFlags.Public);
            entryPoint.Invoke(null, null); // Print out the value of FunctionLibrary.Module.Test, expected to == true
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex);
        }
    }
}

Invoking MyLibrary.OnStartup prints false, not true. I assume I'm just going the wrong way about this, but I'm not really sure how to achieve my goal. I appreciate any help I can get on understanding what I'm doing wrong.

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