control drawing + layered windows

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;


namespace VirtualIpod
{
    public class Base : Form
    {
        public Base()
        {
            InitializeComponent();
        }

        #region Windows Form Designer generated code

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            this.SuspendLayout();
            // 
            // frmSplash
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.BackgroundImageLayout = System.Windows.Forms.ImageLayout.Stretch;
            this.ClientSize = new System.Drawing.Size(323, 197);
            //this.DoubleBuffered = true;
            this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.None;
            this.MouseDown += new MouseEventHandler(Base_MouseDown);
            this.StartPosition = System.Windows.Forms.FormStartPosition.Manual;
            this.Load += new System.EventHandler(this.Form1_Load);
            this.ResumeLayout(false);
        }

        #endregion

        public const int WM_NCLBUTTONDOWN = 0xA1;
        public const int HT_CAPTION = 0x2;

        [DllImportAttribute("user32.dll")]
        public static extern int SendMessage(IntPtr hWnd,
            int Msg, int wParam, int lParam);

        [DllImportAttribute("user32.dll")]
        public static extern bool ReleaseCapture();

        //call functions to move the form in your form's MouseDown event
        private void Base_MouseDown(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                ReleaseCapture();
                SendMessage(Handle, WM_NCLBUTTONDOWN, HT_CAPTION, 0);
            }
        }

        #region CUSTOM PAINT METHODS ----------------------------------------------
        protected override CreateParams CreateParams
        {
            get
            {
                CreateParams cp = base.CreateParams;
                cp.ExStyle |= 0x00080000; // Required: set WS_EX_LAYERED extended style
                return cp;
            }
        }

        //Updates the Form's display using API calls
        public void UpdateFormDisplay(Image backgroundImage)
        {
            IntPtr screenDc = API.GetDC(IntPtr.Zero);
            IntPtr memDc = API.CreateCompatibleDC(screenDc);
            IntPtr hBitmap = IntPtr.Zero;
            IntPtr oldBitmap = IntPtr.Zero;

            try
            {
                //Display-image
                Bitmap bmp = new Bitmap(backgroundImage);
                hBitmap = bmp.GetHbitmap(Color.FromArgb(0));  //Set the fact that background is transparent
                oldBitmap = API.SelectObject(memDc, hBitmap);

                //Display-rectangle
                Size size = bmp.Size;
                Point pointSource = new Point(0, 0);
                Point topPos = new Point(this.Left, this.Top);

                //Set up blending options
                API.BLENDFUNCTION blend = new API.BLENDFUNCTION();
                blend.BlendOp = API.AC_SRC_OVER;
                blend.BlendFlags = 0;
                blend.SourceConstantAlpha = 255;
                blend.AlphaFormat = API.AC_SRC_ALPHA;

                API.UpdateLayeredWindow(this.Handle, screenDc, ref topPos, ref size, memDc, ref pointSource, 0, ref blend, API.ULW_ALPHA);

                //Clean-up
                bmp.Dispose();
                API.ReleaseDC(IntPtr.Zero, screenDc);
                if (hBitmap != IntPtr.Zero)
                {
                    API.SelectObject(memDc, oldBitmap);
                    API.DeleteObject(hBitmap);
                }
                API.DeleteDC(memDc);
            }
            catch (Exception)
            {
            }
        }
        #endregion


        #region FORM EVENTS -------------------------------------------------------
        private void Form1_Load(object sender, EventArgs e)
        {
            UpdateFormDisplay(this.BackgroundImage);
        }

        protected override void OnPaint(PaintEventArgs e)
        {
            //Call our drawing function
            UpdateFormDisplay(this.BackgroundImage);
        }
        #endregion
    }

    internal class API
    {
        public const byte AC_SRC_OVER = 0x00;
        public const byte AC_SRC_ALPHA = 0x01;
        public const Int32 ULW_ALPHA = 0x00000002;

        [StructLayout(LayoutKind.Sequential, Pack = 1)]
        public struct BLENDFUNCTION
        {
            public byte BlendOp;
            public byte BlendFlags;
            public byte SourceConstantAlpha;
            public byte AlphaFormat;
        }

        [DllImport("user32.dll", ExactSpelling = true, SetLastError = true)]
        public static extern bool UpdateLayeredWindow(IntPtr hwnd, IntPtr hdcDst, ref Point pptDst, ref Size psize, IntPtr hdcSrc, ref Point pprSrc, Int32 crKey, ref BLENDFUNCTION pblend, Int32 dwFlags);

        [DllImport("user32.dll", ExactSpelling = true, SetLastError = true)]
        public static extern IntPtr GetDC(IntPtr hWnd);

        [DllImport("gdi32.dll", ExactSpelling = true, SetLastError = true)]
        public static extern IntPtr CreateCompatibleDC(IntPtr hDC);

        [DllImport("user32.dll", ExactSpelling = true)]
        public static extern int ReleaseDC(IntPtr hWnd, IntPtr hDC);

        [DllImport("gdi32.dll", ExactSpelling = true, SetLastError = true)]
        public static extern bool DeleteDC(IntPtr hdc);

        [DllImport("gdi32.dll", ExactSpelling = true)]
        public static extern IntPtr SelectObject(IntPtr hDC, IntPtr hObject);

        [DllImport("gdi32.dll", ExactSpelling = true, SetLastError = true)]
        public static extern bool DeleteObject(IntPtr hObject);
    }
}

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
namespace VirtualIpod
{
    public class Form1 : Base
    {
        private Panel system = new Panel();

        public Form1()
        {
            InitializeComponent();
        }

        private void InitializeComponent()
        {
            System.ComponentModel.ComponentResourceManager resources = new System.ComponentModel.ComponentResourceManager(typeof(Form1));
            this.SuspendLayout();
            //
            // panel
            //
            this.system.Location = new Point(10, 10);
            //
            // Form1
            //
            this.BackgroundImage = ((System.Drawing.Image)(resources.GetObject("$this.BackgroundImage")));
            this.Size = this.BackgroundImage.Size;
            this.StartPosition = FormStartPosition.Manual;
            this.BackgroundImageLayout = System.Windows.Forms.ImageLayout.None;
            this.ClientSize = new System.Drawing.Size(287, 268);
            this.Controls.Add(this.system);
            this.Name = "Form1";
            this.ResumeLayout(false);
        }
    }
}