DBTreeView

using System;
using System.Collections;
using System.Collections.Generic;
using System.ComponentModel;
using System.Text;
using System.Windows.Forms;

namespace WindowsApplication1
{
    internal class DBTreeView : TreeView
    {
        private object rootValue;
        private string parentMember;
        private string childMember;
        private string textMember;

        private object dataSource;
        private CurrencyManager cm;

        public object DataSource
        {
            get { return dataSource; }
            set
            {
                if (value == null)
                {
                    this.cm = null;
                    //this.GroupingChanged();
                }
                else
                {
                    if (!((value is IList) | (value is IListSource)))
                    {
                        throw new Exception("Invalid DataSource");
                    }
                    if (value is IListSource)
                    {
                        IListSource myListSource = (IListSource)value;
                        if (myListSource.ContainsListCollection)
                        {
                            throw new Exception("Invalid DataSource");
                        }
                        this.dataSource = value;
                        this.cm = (CurrencyManager)this.BindingContext[value];
                        //this.GroupingChanged();
                    }
                    else
                    {
                        this.dataSource = value;
                        this.cm = (CurrencyManager)this.BindingContext[value];
                        //this.GroupingChanged();
                    }
                }
            }
        }

        [Category("Data")]
        public string TextMember
        {
            get { return textMember; }
            set { textMember = value; }
        }

        [Category("Data")]
        public string ChildMember
        {
            get { return childMember; }
            set { childMember = value; }
        }

        [Category("Data")]
        public object RootValue
        {
            get { return this.rootValue; }
            set { this.rootValue = value; }
        }

        [Category("Data")]
        public string ParentMember
        {
            get
            {
                return this.parentMember;
            }
            set
            {
                this.parentMember = value;
            }
        }

        public void BuildTree()
        {
            this.Nodes.Clear();

            this.BuildTree(this.Nodes, this.rootValue);
        }

        private void BuildTree(TreeNodeCollection currNodes, object parentValue)
        {
            if ((this.cm != null) && (this.cm.List != null))
            {
                IBindingListView bindingList = this.cm.List as IBindingListView;
                if (bindingList != null && bindingList.SupportsFiltering)
                {
                    bindingList.Filter = string.Format("{0}='{1}'", this.parentMember, parentValue);
                }

                IList innerList = this.cm.List;
                int currentListIndex = 0;
                PropertyDescriptorCollection properties = this.cm.GetItemProperties();
                PropertyDescriptor pdParentMember = properties[this.parentMember];
                PropertyDescriptor pdChildMember = properties[this.childMember];
                PropertyDescriptor pdTextMember = properties[this.textMember];
                //TreeNodeCollection currNodes = this.Nodes;
                while (currentListIndex < innerList.Count)
                {
                    object currObject = innerList[currentListIndex];
                    TreeLeafNode myFirstNode = new TreeLeafNode();
                    myFirstNode.Text = Convert.ToString(pdChildMember.GetValue(currObject));
                    myFirstNode.Value = pdChildMember.GetValue(currObject);
                    myFirstNode.Item = currObject;
                    //this.BuildTree(myFirstNode.Nodes, pdChildMember.GetValue(currObject));
                    currNodes.Add(myFirstNode);

                    currentListIndex += 1;
                }
                for (int i = 0; i < currNodes.Count; i++)
                {
                    TreeLeafNode node = currNodes[i] as TreeLeafNode;
                    this.BuildTree(node.Nodes, node.Value);
                }
            }
        }

    }
}

using System;
using System.Collections.Generic;
using System.Text;
using System.Windows.Forms;

namespace WindowsApplication1
{
    internal  class TreeLeafNode : TreeNode
    {
        private int position;
        private object value;
        private object item;

        public object Item
        {
            get { return item; }
            set { item = value; }
        }

        public object Value
        {
            get { return this.value; }
            set { this.value = value; }
        }

        public int Position
        {
            get { return position; }
            set { position = value; }
        }       
    }
}