C#

MemoryStream ms = new MemoryStream();
            using (ms = GetMemoryStream())
            {
                ms = new MemoryStream(ms.ToArray());

                COPYDATASTRUCT cds;
                cds.dwData = 0;
                cds.lpData = IntPtr.Zero;
                cds.cbData = 0;

                try
                {
                    ms.Flush();
                    ms.Position = 0;
                    
                    int hWnd = FindWindow(null, "Receive");
                    int dataSize = Convert.ToInt32(ms.Length);

                    cds.dwData = 0;
                    cds.lpData = Marshal.AllocCoTaskMem(dataSize);
                    cds.cbData = dataSize;

                    SendMessage(hWnd, WM_COPYDATA, 0, ref cds);
                }
                finally
                {
                    Marshal.FreeCoTaskMem(cds.lpData);
                    ms.Close();
                }
            }

Type unboundWEMType = typeof(WeakEventManager<,>);
Type[] typeArgs = { _sender.Target.GetType(), typeof(EventArgs) };
Type constructedWEMType = unboundWEMType.MakeGenericType(typeArgs);

Kenneth Haugland wrote:

It's a pain.

Richard Deeming wrote:

t might be important to know which one was used in the type.

using System;
using System.Collections.Generic;
using System.Text;

namespace YLScsDrawing.Drawing3d
{
    public struct Quaternion
    {
        public double X, Y, Z, W;

        public Quaternion(double w, double x, double y, double z)// This is the set of parameters I wish to call...
        {
            W = w; X = x; Y = y; Z = z;
        }
     }
}

Quaternion quat = new Quaternion ((double)absW, (double)absX, (double)absY, (double)absZ));
Thread absoluteThread = new Thread(unused => Program.PassStructIn(ref quat);