C#

ToolStripItem[] newitems = new ToolStripItem[myToolStripMenuItem.DropDownItems.Count];
myToolStripMenuItem.DropDownItems.CopyTo(newitems, 0);
myToolStripDropDownButton.DropDownItems.AddRange(newitems);

public partial class Form1 : Form
{
  IServiceContainer isc;
  DesignSurface ds;
  IDesignerHost idh;
  ISelectionService iss;  
  IToolboxUser itu;  
  MyToolBox toolbox;

  public Form1()
  {
   // Create the DesignSurface and load it with a form   
   isc = new ServiceContainer();
   ds = new DesignSurface(isc);   
   ds.BeginLoad(typeof(Form));

   idh = (IDesignerHost)ds.GetService(typeof(IDesignerHost));
   iss = (ISelectionService)ds.GetService(typeof(ISelectionService));
   itu = (IToolboxUser)idh.GetDesigner(idh.RootComponent);   
   
   InitializeComponent();

   iss.SelectionChanged += new EventHandler(iss_SelectionChanged);
  }

  private void Form1_Load(object sender, EventArgs e)
  {
   toolbox = new MyToolBox();
   toolbox.Dock = DockStyle.Fill;
   splitContainer1.Panel1.Controls.Add(toolbox);
   isc.AddService(typeof(IToolboxService), toolbox);

   // Get the View of the DesignSurface, host it in a form, and show it
   Control c = ds.View as Control;
   c.Parent = this.splitContainer2.Panel1;
   c.Dock = DockStyle.Fill;
  }

  private void iss_SelectionChanged(object sender, EventArgs e)
  {
   propertyGrid1.SelectedObject = iss.PrimarySelection;
  }
}

Cross-thread operation not valid: Control 'lbConnections' accessed from a thread other than the thread it was created on.

using System;
using System.Text;
using System.Windows.Forms;
using System.Net.Sockets;

namespace UDP_Client
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            UdpClient udpClient = new UdpClient();
            udpClient.Connect(tbHost.Text, 8080);
            Byte[] sendBytes = Encoding.ASCII.GetBytes("Hello World?");
            udpClient.Send(sendBytes, sendBytes.Length);
        }

        private void Form1_Load(object sender, EventArgs e)
        {

        }
    }
}

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Threading;
using System.Net;
using System.Net.Sockets;


namespace UDP_Server
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }


        public void serverThread()
        {
            UdpClient udpClient = new UdpClient(8080);
            while (true)
            {
                IPEndPoint RemoteIpEndPoint = new IPEndPoint(IPAddress.Any, 0);
                Byte[] receiveBytes = udpClient.Receive(ref RemoteIpEndPoint);
                string returnData = Encoding.ASCII.GetString(receiveBytes);
                lbConnections.Items.Add(RemoteIpEndPoint.Address.ToString() + ":" +
                returnData.ToString()
                );
            }
        }
        

        private void Form1_Load(object sender, EventArgs e)
        {

            Thread thdUDPServer = new Thread(new
                                    ThreadStart(serverThread));
            thdUDPServer.Start();
        }
    }
}