extends TreeView : TreeView « System.Windows.Forms « C# / C Sharp by API

1. C# / C Sharp by API
2. System.Windows.Forms
3. TreeView

extends TreeView

 
/*
User Interfaces in C#: Windows Forms and Custom Controls
by Matthew MacDonald

Publisher: Apress
ISBN: 1590590457
*/

using System.IO;

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;

namespace DirectoryTreeHost
{
    /// <summary>
    /// Summary description for DirectoryTreeHost.
    /// </summary>
    public class DirectoryTreeHost : System.Windows.Forms.Form
    {
        /// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ComponentModel.Container components = null;

        public DirectoryTreeHost()
        {
            //
            // Required for Windows Form Designer support
            //
            InitializeComponent();

            //
            // TODO: Add any constructor code after InitializeComponent call
            //
        }

        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        protected override void Dispose( bool disposing )
        {
            if( disposing )
            {
                if(components != null)
                {
                    components.Dispose();
                }
            }
            base.Dispose( disposing );
        }

        #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()
        {
            // 
            // DirectoryTreeHost
            // 
            this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
            this.ClientSize = new System.Drawing.Size(292, 266);
            this.Name = "DirectoryTreeHost";
            this.Text = "DirectoryTreeHost";
            this.Load += new System.EventHandler(this.DirectoryTreeHost_Load);

        }
        #endregion

        private void DirectoryTreeHost_Load(object sender, System.EventArgs e)
        {
            DirectoryTree dirTree = new 
                DirectoryTree();
            dirTree.Size = new Size(this.Width - 30, this.Height - 60);
            dirTree.Location = new Point(5, 5);
            dirTree.Drive = Char.Parse("C");
            this.Controls.Add(dirTree);

        }

        public static void Main()
        {
            Application.Run(new DirectoryTreeHost());
        }
    }
    public class DirectoryTree : TreeView
    {
        public delegate void DirectorySelectedDelegate(object sender,
            DirectorySelectedEventArgs e);
        public event DirectorySelectedDelegate DirectorySelected;
        
        private Char drive;
        public Char Drive
        {
            get
            {
                return drive;
            }
            set
            {
                drive = value;
                RefreshDisplay();
            }
        }
        
        // This is public so a Refresh can be triggered manually.
        public void RefreshDisplay()
        {
            // Erase the existing tree.
            this.Nodes.Clear();
            
            // Set the first node.
            TreeNode rootNode = new TreeNode(drive + ":\\");
            this.Nodes.Add(rootNode);
            
            // Fill the first level and expand it.
            Fill(rootNode);
            this.Nodes[0].Expand();
        }
        
        private void Fill(TreeNode dirNode)
        {
            DirectoryInfo dir = new DirectoryInfo(dirNode.FullPath);
            
            // An exception could be thrown in this code if you don't
            // have sufficient security permissions for a file or directory.
            // You can catch and then ignore this exception.
            
            foreach (DirectoryInfo dirItem in dir.GetDirectories())
            {
                // Add node for the directory.
                TreeNode newNode = new TreeNode(dirItem.Name);
                dirNode.Nodes.Add(newNode);
                newNode.Nodes.Add("*");
            }
        }
        
        protected override void OnBeforeExpand(TreeViewCancelEventArgs e)
        {
            base.OnBeforeExpand(e);

            // If a dummy node is found, remove it and read the real directory list.
            if (e.Node.Nodes[0].Text == "*")
            {
                e.Node.Nodes.Clear();
                Fill(e.Node);
            }
        }
        
        protected override void OnAfterSelect(TreeViewEventArgs e)
        {
            base.OnAfterSelect(e);
            
            // Raise the DirectorySelected event.
            if (DirectorySelected != null)
            {
                DirectorySelected(this,
                    new DirectorySelectedEventArgs(e.Node.FullPath));
            }
        }
    }
    public class DirectorySelectedEventArgs : EventArgs
    {
        public string DirectoryName;

        public DirectorySelectedEventArgs(string directoryName)
        {
            this.DirectoryName = directoryName;
        }
    }



}

   
  

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