GUI Windows Form C#

/*
User Interfaces in C#: Windows Forms and Custom Controls
by Matthew MacDonald
Publisher: Apress
ISBN: 1590590457
*/
using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
namespace TreeViewExample
{
    /// 
    /// Summary description for TreeViewExample.
    /// 

    public class TreeViewExample : System.Windows.Forms.Form
    {
        internal System.Windows.Forms.TreeView treeFood;
        /// 
        /// Required designer variable.
        /// 

        private System.ComponentModel.Container components = null;
        public TreeViewExample()
        {
            //
            // Required for Windows Form Designer support
            //
            InitializeComponent();
            //
            // 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.treeFood = new System.Windows.Forms.TreeView();
            this.SuspendLayout();
            // 
            // treeFood
            // 
            this.treeFood.Anchor = (((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom) 
                | System.Windows.Forms.AnchorStyles.Left) 
                | System.Windows.Forms.AnchorStyles.Right);
            this.treeFood.ImageIndex = -1;
            this.treeFood.Location = new System.Drawing.Point(4, 5);
            this.treeFood.Name = "treeFood";
            this.treeFood.SelectedImageIndex = -1;
            this.treeFood.Size = new System.Drawing.Size(284, 256);
            this.treeFood.TabIndex = 1;
            this.treeFood.AfterSelect += new System.Windows.Forms.TreeViewEventHandler(this.treeFood_AfterSelect);
            // 
            // TreeViewExample
            // 
            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.treeFood});
            this.Name = "TreeViewExample";
            this.Text = "TreeView Example";
            this.Load += new System.EventHandler(this.TreeViewExample_Load);
            this.ResumeLayout(false);
        }
        #endregion
        /// 
        /// The main entry point for the application.
        /// 

        [STAThread]
        static void Main() 
        {
            Application.Run(new TreeViewExample());
        }
        private void TreeViewExample_Load(object sender, System.EventArgs e)
        {
            TreeNode node;
            
            node = treeFood.Nodes.Add("Fruits");
            node.Nodes.Add("Apple");
            node.Nodes.Add("Peach");
            
            node = treeFood.Nodes.Add("Vegetables");
            node.Nodes.Add("Tomato");
            node.Nodes.Add("Eggplant");
        }
        private void treeFood_AfterSelect(object sender, System.Windows.Forms.TreeViewEventArgs e)
        {
            if (e.Action == TreeViewAction.ByMouse)
            {
                MessageBox.Show(e.Node.FullPath);
            }
        }
    }
}