2D Graphics C#

/*
Professional Windows GUI Programming Using C#
by Jay Glynn, Csaba Torok, Richard Conway, Wahid Choudhury, 
   Zach Greenvoss, Shripad Kulkarni, Neil Whitlow
Publisher: Peer Information
ISBN: 1861007663
*/
using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
namespace KnownColors
{
    /// 
    /// Summary description for KnownColors.
    /// 

    public class KnownColors : System.Windows.Forms.Form
    {
        private System.Windows.Forms.ComboBox comboBox1;
        /// 
        /// Required designer variable.
        /// 

        private System.ComponentModel.Container components = null;
        ArrayList cAL;
        ArrayList cNAL;
        public KnownColors()
        {
            //
            // Required for Windows Form Designer support
            //
            InitializeComponent();
            
            this.Text = "Known non-system colors";
            
            cAL = new ArrayList();      // colors
            cNAL = new ArrayList();      // strings
            NonSystemColors(cAL, cNAL);
            this.comboBox1.Sorted = true;
            this.comboBox1.DataSource = cNAL; //set the combo's data source
            //
            // TODO: Add any constructor code after InitializeComponent call
            //
        }
        /// 
        /// Clean up any resources being used.
        /// 

        protected override void Dispose( bool disposing )
        {
            if( disposing )
            {
                if (components != null) 
                {
                    components.Dispose();
                }
            }
            base.Dispose( disposing );
        }
        #region Windows Form Designer generated code
        /// 
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// 

        private void InitializeComponent()
        {
            this.comboBox1 = new System.Windows.Forms.ComboBox();
            this.SuspendLayout();
            // 
            // comboBox1
            // 
            this.comboBox1.Location = new System.Drawing.Point(8, 8);
            this.comboBox1.Name = "comboBox1";
            this.comboBox1.Size = new System.Drawing.Size(121, 21);
            this.comboBox1.TabIndex = 0;
            this.comboBox1.Text = "comboBox1";
            // 
            // KnownColors
            // 
            this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
            this.ClientSize = new System.Drawing.Size(292, 266);
            this.Controls.AddRange(new System.Windows.Forms.Control[] {
                                                                          this.comboBox1});
            this.Name = "KnownColors";
            this.Text = "KnownColors";
            this.ResumeLayout(false);
        }
        #endregion
        /// 
        /// The main entry point for the application.
        /// 

        [STAThread]
        static void Main() 
        {
            Application.Run(new KnownColors());
        }
        private void NonSystemColors(ArrayList cAL, ArrayList cNAL)
        {
            Array cA = Enum.GetValues(typeof(KnownColor));
            foreach(KnownColor knwnC in cA)  // cX.Length = 167
            {
                Color curC = Color.FromKnownColor(knwnC); 
                if(!curC.IsSystemColor) 
                {
                    cAL.Add(curC);
                    cNAL.Add(curC.Name.ToString());
                }
            }
        }
        protected override void OnPaint(PaintEventArgs pea)
        {
            Graphics g = pea.Graphics;
            int wi = 70, hi = 12, rectNb = 8; 
            int cALNb = cAL.Count;
            this.Width = (wi +2)*rectNb + 9;
            int y = (int)(cALNb / rectNb);
            this.Height = y*(2 + hi) + 60;
            DisplayKnownColors(g, cALNb, wi, hi, rectNb);
            g.Dispose();
        }
        private void DisplayKnownColors(Graphics g, int cALNb, int wi, int hi, int rectNb)
        {
            Rectangle rec;
            Pen p = new Pen(this.ForeColor);
            Brush b;
            StringFormat strfmt = new StringFormat();
            strfmt.LineAlignment = strfmt.Alignment = StringAlignment.Near;
            int x, y;
            for (int i = 0; i < cALNb; i++)
            {
                x = (int)(i % rectNb);
                y = (int)(i / rectNb);
                rec = new Rectangle(1 + x*(2 + wi), 1 + y*(2 + hi), wi, hi);
                g.DrawRectangle(p, rec);
                b  = new SolidBrush((Color)cAL[i]);
                g.FillRectangle(b, rec);
                b  = new SolidBrush(Color.Black);
                g.DrawString((string)cNAL[i], this.Font, b, rec, strfmt);
            }
            x = (int)(cALNb % rectNb);
            y = (int)(cALNb / rectNb);
            this.comboBox1.Location = new Point(x*(wi + 2) + 2, y*(2 + hi) + 2);
        }
    }
}