A .NET Wizard control

using System;
using System.Collections;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Windows.Forms;
using System.Diagnostics;
using UtilityLibrary.General;
using UtilityLibrary.Win32;

namespace UtilityLibrary.WinControls
{
  
  /// <summary>
  /// Summary description for CheckBoxEx.
  /// </summary>
  //[ToolboxItem(false)]
  public class CheckBoxEx : System.Windows.Forms.CheckBox
  {
    
    #region Class Variables
    const int CHECK_MARK_SIZE = 11;
    DrawState drawState = DrawState.Normal;
    Bitmap checkMarkChecked = null;
    Bitmap checkMarkUnchecked = null;
    Bitmap checkMarkHotChecked = null;
    Bitmap checkMarkHotUnchecked = null;
    Bitmap checkMarkDisableChecked = null;
    Bitmap checkMarkDisableUnchecked = null;
    Color oldHighLightColor = Color.Empty;
    Color oldControlDarkColor = Color.Empty;
    #endregion
    
    #region Constructors
    public CheckBoxEx()
    {
      // Our control needs to have Flat style set
      FlatStyle = FlatStyle.Flat;
      // Load checkmark bitmap
      checkMarkChecked = ResourceUtil.LoadBitmapResource(Type.GetType("UtilityLibrary.WinControls.CheckBoxEx"),
        "UtilityLibrary.Resources.Controls", "CheckMarkChecked");
      Debug.Assert(checkMarkChecked != null);
      checkMarkUnchecked = ResourceUtil.LoadBitmapResource(Type.GetType("UtilityLibrary.WinControls.CheckBoxEx"),
        "UtilityLibrary.Resources.Controls", "CheckMarkUnchecked");
      Debug.Assert(checkMarkUnchecked != null);
    }

    #endregion

    #region Overrides
    protected override void OnMouseEnter(EventArgs e)
    {
      // Set state to hot
      base.OnMouseEnter(e);
      drawState = DrawState.Hot;
      Invalidate();
    }

    protected override void OnMouseLeave(EventArgs e)
    {
      // Set state to Normal
      base.OnMouseLeave(e);
      if ( !ContainsFocus )
      {
        drawState = DrawState.Normal;
        Invalidate();
      }
    }
      
    protected override void OnGotFocus(EventArgs e)
    {
      // Set state to Hot
      base.OnGotFocus(e);
      drawState = DrawState.Hot;
      Invalidate();
    }
        
    protected override void OnLostFocus(EventArgs e)
    {
      // Set state to Normal
      base.OnLostFocus(e);
      drawState = DrawState.Normal;
      Invalidate();
    }

    protected override  void WndProc(ref Message m)
    {
      bool callBase = true;
            
      switch(m.Msg)
      {
        case ((int)Msg.WM_PAINT):
        {
          // Let the edit control do its painting
          base.WndProc(ref m);
          // Now do our custom painting
          DrawCheckBoxState(Enabled?drawState:DrawState.Disable);
          callBase = false;
        }
          break;
        default:
          break;
      }

      if ( callBase )
        base.WndProc(ref m);
    
    }

    #endregion

    #region Properties
    public new FlatStyle FlatStyle 
    {
      // Don't let the user change this property
      // to anything other than flat, otherwise
      // there would be painting problems
      get { return base.FlatStyle; } 
      set 
      {
        if ( value != FlatStyle.Flat )
        {
          // Throw an exception to tell the user
          // that this property needs to be "Flat" 
          // if he is to use this class
          string message = "FlatStyle needs to be set to Flat for this class";
          ArgumentException argumentException = new ArgumentException("FlatStyle", message);
          throw(argumentException);
        }
        else 
          base.FlatStyle = value;
      }
    }

    #endregion

    #region Implementation
    void DrawCheckBoxState(DrawState state)
    {
      // In case system colors has changed
      FilterImages();
      Rectangle rect = ClientRectangle;

      // Create DC for the whole edit window instead of just for the client area
      IntPtr hDC = WindowsAPI.GetDC(Handle);
      Rectangle checkMark = new Rectangle(rect.Left, rect.Top + (rect.Height-CHECK_MARK_SIZE)/2, 
        CHECK_MARK_SIZE, CHECK_MARK_SIZE);
      
      using (Graphics g = Graphics.FromHdc(hDC))
      {
        if ( state == DrawState.Normal )
        {
          // Draw normal black circle
          if ( Checked ) 
            g.DrawImage(checkMarkChecked, checkMark.Left, checkMark.Top);
          else
            g.DrawImage(checkMarkUnchecked, checkMark.Left, checkMark.Top);
        }
        else if ( state == DrawState.Hot )
        {
          if ( Checked ) 
            g.DrawImage(checkMarkHotChecked, checkMark.Left, checkMark.Top);
          else
            g.DrawImage(checkMarkHotUnchecked, checkMark.Left, checkMark.Top);
          
        }
        else if ( state == DrawState.Disable )
        {
          if ( Checked ) 
            g.DrawImage(checkMarkDisableChecked, checkMark.Left, checkMark.Top);
          else
            g.DrawImage(checkMarkDisableUnchecked, checkMark.Left, checkMark.Top);
        }
      }

      // Release DC
      WindowsAPI.ReleaseDC(Handle, hDC);
    }

    void FilterImages()
    {
      // Filter images only if the color information has
      // changed or if this is the first time we are getting it
      if ( oldHighLightColor == Color.Empty ||
        !(oldHighLightColor.R == ColorUtil.VSNetBorderColor.R && oldHighLightColor.G == ColorUtil.VSNetBorderColor.G
        && oldHighLightColor.B == ColorUtil.VSNetBorderColor.B ) )
      {
        oldHighLightColor = ColorUtil.VSNetBorderColor;
        checkMarkHotChecked = DoFiltering(checkMarkChecked, Color.Black, ColorUtil.VSNetBorderColor);
        checkMarkHotUnchecked = DoFiltering(checkMarkUnchecked, Color.Black, ColorUtil.VSNetBorderColor);
      }

      if ( oldControlDarkColor == Color.Empty ||
        !(oldHighLightColor.R == ColorUtil.VSNetBorderColor.R && oldHighLightColor.G == ColorUtil.VSNetBorderColor.G
        && oldHighLightColor.B == ColorUtil.VSNetBorderColor.B ) )
      {
        oldControlDarkColor = SystemColors.ControlDark;
        checkMarkDisableChecked = DoFiltering(checkMarkChecked, Color.Black, SystemColors.ControlDark);
        checkMarkDisableUnchecked = DoFiltering(checkMarkUnchecked, Color.Black, SystemColors.ControlDark);
      }
    }

    Bitmap DoFiltering(Bitmap bitmap, Color oldColor, Color newColor)
    {
      Bitmap copy = (Bitmap)bitmap.Clone();
      for ( int i = 0; i < bitmap.Width; i++ )
      {
        for ( int j = 0; j < bitmap.Height; j++ )
        {
          Color currentPixel = copy.GetPixel(i, j);
          // Compare just RGB portion
          if ( currentPixel.R == oldColor.R && currentPixel.G == oldColor.G
            && currentPixel.B == oldColor.B)
            copy.SetPixel(i, j, newColor);
        }
      }
      return copy;
    }

    #endregion
      
  }

}