Help with managed DLL injection

[wowsc4p3]

I had GreyMagic working a while ago, but it involved compiling 2 other things (1 dll, 1 executable and the injected classes DLL). I have since lost the code, and forgotten how to inject a managed .net DLL into the application.
I've been trying all of the options available, and none seem to work. This is the code I have:

using System;using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Diagnostics;
using System.Runtime.InteropServices;
using GreyMagic;
using System.Windows.Forms;
namespace WoWHack
{
    public class Class1
    {
        [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
        public delegate int FrameScript_ExecuteBufferDelegate(byte a, IntPtr addr, IntPtr addrStr);
        public FrameScript_ExecuteBufferDelegate FrameScript_ExecuteBuffer;
        public void main()
        {
            Process p = Process.GetCurrentProcess();
            
            InProcessMemoryReader Memory = new InProcessMemoryReader(p);
            FrameScript_ExecuteBuffer = Memory.CreateFunction<FrameScript_ExecuteBufferDelegate>((IntPtr)0x4F9EC, true);
            string str = "print('test');";
            IntPtr buff = Marshal.AllocHGlobal(str.Length + 0x100);
            Memory.WriteString(buff, str, Encoding.UTF8);
            FrameScript_ExecuteBuffer(0, buff, buff);
            Marshal.FreeHGlobal(buff);
        }
        public static int DllMain(string p)
        {
            MessageBox.Show(p, "Managed MessageBox", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
            new Class1().main();
            return -1;
        }
    }
}

However, No messagebox is shown, and generally there is some kind of error.
What should I do? Are there any pre-made applications to inject a .net dll into a native process?

Thanks for reading.

[Jadd]

http://www.ownedcore.com/forums/worl...-injector.html (Yet another dll injector..)

[wowsc4p3]

That didn't work when I tried (It gave me error -2 billion). I found a working one elsewhere though and modified the process list to only list wow.
Thanks anyway.

[Jadd]

-2 billion is probably an error code which would be useful to you. Convert it to hex and find which error it is.