Create TreeView Structure From Data Table in ASP.Net

One of my friend want to convert Datatable to Tree Structure, hope this will help you.

class Program

{

static void Main(string[] args)

{

try

{

DataTable dt = new DataTable();

dt.Columns.Add(new DataColumn("Id", Type.GetType("System.Int32")));

dt.Columns.Add(new DataColumn("Name"));

dt.Columns.Add(new DataColumn("ParentNodeId", Type.GetType("System.Int32")));

DataRow dr = dt.NewRow();

dr[0] = "1";

dr[1] = "Number 1";

dr[2] = "0";

dt.Rows.Add(dr);

dr = dt.NewRow();

dr[0] = "2";

dr[1] = "Number 2";

dr[2] = "1";

dt.Rows.Add(dr);

dr = dt.NewRow();

dr[0] = "3";

dr[1] = "Number 3";

dr[2] = "2";

dt.Rows.Add(dr);

dr = dt.NewRow();

dr[0] = "4";

dr[1] = "Number 4";

dr[2] = "1";

dt.Rows.Add(dr);

new CreateTreeNode(dt, "Id", "Name", "ParentNodeId");

Console.WriteLine("Table Created...");

}

catch (Exception ex)

{

Console.WriteLine(ex.Message.ToString());

}

Console.ReadKey();

}

}

public class TreeNode

{

public int Id { set; get; }

public string Name { get; set; }

public int ParentId { get; set; }

public List ChildeNodes { get; set; }

public TreeNode()

{

this.Id = this.ParentId = 0;

this.Name = string.Empty;

this.ChildeNodes = new List();

}

public TreeNode(int TreeNodeId, string TreeNodeName, int ParentNodeId)

: base()

{

this.Id = TreeNodeId;

this.Name = TreeNodeName;

this.ParentId = ParentNodeId;

}

}

public class CreateTreeNode

{

List _nodeList;

DataTable _dataTable;

string _nodeColumn;

string _displayNodeColumn;

string _parentNodeColumn;

CreateTreeNode()

{

this._nodeList = new List();

this._dataTable = new DataTable("TreeView");

}

public CreateTreeNode(DataTable dataTable, string NodeColumn, string DisplayNodeColumn, string ParentNodeColumn)

: base()

{

this._dataTable = dataTable;

this._nodeColumn = NodeColumn;

this._displayNodeColumn = DisplayNodeColumn;

this._parentNodeColumn = ParentNodeColumn;

this._nodeList = CreateTreeView(0);

int i = 0;

i++;

}

List CreateTreeView(int parentNodeId)

{

List nodeList;

DataRow[] SelectedRow = this._dataTable.Select(string.Format("{0}={1}", this._parentNodeColumn, parentNodeId));

TreeNode currentNode;

if (SelectedRow.Length <= 0)

return new List();

else

nodeList = new List();

foreach (DataRow currentRow in SelectedRow)

{

currentNode = new TreeNode();

currentNode.Id = Convert.ToInt32(currentRow[this._nodeColumn].ToString());

currentNode.Name = currentRow[this._displayNodeColumn].ToString();

currentNode.ParentId = Convert.ToInt32(currentRow[this._parentNodeColumn].ToString());

currentNode.ChildeNodes = CreateTreeView(currentNode.Id);

nodeList.Add(currentNode);

}

return nodeList;

}

}