RadTreeView for ASP.NET
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Saving changes made in Telerik RadTreeView to a database Send comments on this topic.
Example scenarios (How to) > Server-side > Saving changes made in Telerik RadTreeView to a database

Glossary Item Box

This example demonstrates a simple mechanism using Access database with single self-referencing table containing columns id, parentId and Text.

The structure of the treeview is loaded from this database in the Page_Load event. Then the user edits the text of random nodes in the treeview and hits the Save button on the page. Thus, a postback is triggered and the updated information is saved back in the database file.

The code below shows the approach:

Example:

C# Copy Code
protected System.Web.UI.WebControls.Button Button1;
protected Telerik.WebControls.RadTreeView RadTree1;
protected OleDbCommand command;
protected OleDbConnection con;

private void GenerateTreeView()
{
  OleDbConnection dbCon = new OleDbConnection ("Provider=Microsoft.Jet.OLEDB.4.0;Data
  Source=" + Server.MapPath("treeSave.mdb"));
  //the database is in the web app root!
  dbCon.Open();

  OleDbDataAdapter adapter = new OleDbDataAdapter("SELECT * FROM Links", dbCon);
  DataSet ds = new DataSet();
  adapter.Fill(ds);

  ds.Relations.Add("NodeRelation", ds.Tables[0].Columns["id"], ds.Tables[0].Columns
  ["parentId"]);

  foreach(DataRow dbRow in ds.Tables[0].Rows)
  {
   if(dbRow.IsNull("parentId"))
   {
    RadTreeNode node = CreateNode(dbRow["Text"].ToString(), true);
    RadTree1.AddNode(node);
    RecursivelyPopulate(dbRow, node);
   }
  }
}

private void RecursivelyPopulate(DataRow dbRow, RadTreeNode node)
{
  foreach (DataRow childRow in dbRow.GetChildRows("NodeRelation"))
  {
   RadTreeNode childNode = CreateNode(childRow["Text"].ToString(), true);
   node.AddNode(childNode);
   RecursivelyPopulate(childRow, childNode);
  }
}

private RadTreeNode CreateNode(string text, bool expanded)
{
  RadTreeNode node = new RadTreeNode(text);
  node.Expanded = true;

  return node;
}

private void Page_Load(object sender, System.EventArgs e)
{
  if (!Page.IsPostBack)
  {
   GenerateTreeView();
  }
}


private void RadTree1_NodeEdit(object o, Telerik.WebControls.RadTreeNodeEventArgs e)
{
  RadTreeNode edit = e.NodeEdited;
  String text = e.NewText;
  edit.Text = text;
}

private void Button1_Click(object sender, System.EventArgs e)
{
  con = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" +
  Server.MapPath("treeSave.mdb"));
  con.Open();

  command = new OleDbCommand("DELETE * from Links",con);
  command.ExecuteNonQuery();
  con.Close();
  UpdateNodes();
}
private void UpdateNodes()
{
  OleDbConnection con = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data
  Source=" + Server.MapPath("treeSave.mdb"));
  con.Open();

  ArrayList allNodes = RadTree1.GetAllNodes();
  for(int i = 0; i < allNodes.Count; i++)
  {
   RadTreeNode node = (RadTreeNode)allNodes[i];
   int parentId = allNodes.IndexOf(node.Parent);

   command = new OleDbCommand("INSERT into Links([id],parentId,[Text]) values
   (@ID,@parentId,@Text)",con);
   command.Parameters.Add("ID",i.ToString());
   if(parentId > -1)
     command.Parameters.Add("parentId",parentId);
   else
     command.Parameters.Add("parentId",System.DBNull.Value);
   command.Parameters.Add("Text",node.Text);
   command.ExecuteNonQuery();

  }
  con.Close();
}
        
VB.NET Copy Code
Imports Telerik.WebControls
Imports System.Data.OleDb

    Private Sub GenerateTreeView()
        Dim dbCon As New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Server.MapPath("treeSave.mdb"))
        dbCon.Open()

        Dim adapter As New OleDbDataAdapter("SELECT * FROM Links", dbCon)
        Dim ds As New DataSet
        adapter.Fill(ds)

        ds.Relations.Add("NodeRelation", ds.Tables(0).Columns("id"), ds.Tables(0).Columns("parentId"))

        Dim dbRow As DataRow
        For Each dbRow In ds.Tables(0).Rows
            If dbRow.IsNull("parentId") Then
                Dim node As RadTreeNode = CreateNode(dbRow("Text").ToString(), True)
                RadTree1.AddNode(node)
                RecursivelyPopulate(dbRow, node)
            End If
        Next dbRow
    End Sub 'GenerateTreeView


    Private Sub RecursivelyPopulate(ByVal dbRow As DataRow, ByVal node As RadTreeNode)
        Dim childRow As DataRow
        For Each childRow In dbRow.GetChildRows("NodeRelation")
            Dim childNode As RadTreeNode = CreateNode(childRow("Text").ToString(), True)
            node.AddNode(childNode)
            RecursivelyPopulate(childRow, childNode)
        Next childRow
    End Sub 'RecursivelyPopulate


    Private Function CreateNode(ByVal [text] As String, ByVal expanded As Boolean) As RadTreeNode
        Dim node As New RadTreeNode([text])
        node.Expanded = True

        Return node
    End Function 'CreateNode


    Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        If Not Page.IsPostBack Then
            GenerateTreeView()
        End If
    End Sub 'Page_Load
    Private Sub RadTree1_NodeEdit(ByVal o As Object, ByVal e As Telerik.WebControls.RadTreeNodeEventArgs) Handles RadTree1.NodeEdit
        Dim edit As RadTreeNode = e.NodeEdited
        Dim [text] As String = e.NewText
        edit.Text = [text]
    End Sub 'RadTree1_NodeEdit


    Private Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
        con = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Server.MapPath("treeSave.mdb"))
        con.Open()
        command = New OleDbCommand("DELETE * from Links", con)
        command.ExecuteNonQuery()
        con.Close()
        UpdateNodes()
    End Sub 'Button1_Click

    Private Sub UpdateNodes()
        Dim con As New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Server.MapPath("treeSave.mdb"))
        con.Open()

        Dim allNodes As ArrayList = RadTree1.GetAllNodes()
        Dim i As Integer
        For i = 0 To allNodes.Count - 1
            Dim node As RadTreeNode = CType(allNodes(i), RadTreeNode)
            Dim parentId As Integer = allNodes.IndexOf(node.Parent)

            command = New OleDbCommand("INSERT into Links([id],parentId,[Text]) values (@ID,@parentId,@Text)", con)
            command.Parameters.Add("ID", i.ToString())
            If parentId > -1 Then
                command.Parameters.Add("parentId", parentId)
            Else
                command.Parameters.Add("parentId", System.DBNull.Value)
            End If
            command.Parameters.Add("Text", node.Text)
            command.ExecuteNonQuery()
        Next i
        con.Close()
    End Sub 'UpdateNodes
End Class 'WebForm1