Saving changes made in RadTreeView to a database manually

How to

Save the changes made in RadTreeView to a database.

Solution

The example demonstrates a simple mechanism to attain such functionality 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 PageLoad. 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.
Please review the code below for your better understanding:

ASPX

    private void GenerateTreeView() 
    { 
        OleDbConnection dbCon = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Server.MapPath("App_Data/Tree.mdb")); 
        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); 
                RadTreeView1.Nodes.Add(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.Nodes.Add(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(); 
        } 
    } 
    protected void RadTreeView1_NodeEdit(object o, RadTreeNodeEditEventArgs e) 
    { 
        RadTreeNode edit = e.Node; 
        edit.Text = e.Text; 
    } 
    protected void Button1_Click(object sender, System.EventArgs e) 
    { 
        OleDbConnection con = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Server.MapPath("App_Data/Tree.mdb")); 
        OleDbCommand command = new OleDbCommand("DELETE * from Links", con); 
        con.Open(); 
        command.ExecuteNonQuery(); 
        con.Close(); 
        UpdateNodes(); 
    } 
    private void UpdateNodes() 
    { 
        OleDbConnection con = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Server.MapPath("App_Data/Tree.mdb")); 
        con.Open(); 
        IList<RadTreeNode> allNodes = RadTreeView1.GetAllNodes(); 
        for (int i = 0; i < allNodes.Count; i++) 
        { 
            RadTreeNode node = (RadTreeNode) allNodes[i]; 
            int parentId = allNodes.IndexOf(node.ParentNode); 
            OleDbCommand command = new OleDbCommand("INSERT into Links([id], parentId,[Text]) values (@ID,@parentId,@Text)", con); 
            command.Parameters.AddWithValue("ID", i.ToString()); 
            if (parentId > -1) 
            { 
                command.Parameters.AddWithValue("parentId", parentId); 
            } 
            else 
            { 
                command.Parameters.AddWithValue("parentId", System.DBNull.Value); 
            } 
            command.Parameters.AddWithValue("Text", node.Text); 
            command.ExecuteNonQuery(); 
        } 
        con.Close(); 
    } 

VB

    Private Sub GenerateTreeView() 
        Dim dbCon As New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Server.MapPath("App_Data/Tree.mdb")) 
        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")) 
        For Each dbRow As DataRow In ds.Tables(0).Rows 
            If dbRow.IsNull("parentId") Then 
                Dim node As RadTreeNode = CreateNode(dbRow("Text").ToString(), True) 
                RadTreeView1.Nodes.Add(node) 
                RecursivelyPopulate(dbRow, node) 
            End If 
        Next 
    End Sub 
    Private Sub RecursivelyPopulate(ByVal dbRow As DataRow, ByVal node As RadTreeNode) 
        For Each childRow As DataRow In dbRow.GetChildRows("NodeRelation") 
            Dim childNode As RadTreeNode = CreateNode(childRow("Text").ToString(), True) 
            node.Nodes.Add(childNode) 
            RecursivelyPopulate(childRow, childNode) 
        Next 
    End Sub 
    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 
    Private Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load 
        If Not Page.IsPostBack Then 
            GenerateTreeView() 
        End If 
    End Sub 
    Protected Sub RadTreeView1_NodeEdit(ByVal o As Object, ByVal e As RadTreeNodeEditEventArgs) 
        Dim edit As RadTreeNode = e.Node 
        edit.Text = e.Text 
    End Sub 
    Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) 
        Dim con As New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Server.MapPath("App_Data/Tree.mdb")) 
        Dim command As New OleDbCommand("DELETE * from Links", con) 
        con.Open() 
        command.ExecuteNonQuery() 
        con.Close() 
        UpdateNodes() 
    End Sub 
    Private Sub UpdateNodes() 
        Dim con As New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Server.MapPath("App_Data/Tree.mdb")) 
        con.Open() 
        Dim allNodes As IList(Of RadTreeNode) = RadTreeView1.GetAllNodes() 
        Dim i As Integer 
        For i = 0 To allNodes.Count - 1 
            Dim node As RadTreeNode = DirectCast(allNodes(i), RadTreeNode) 
            Dim parentId As Integer = allNodes.IndexOf(node.ParentNode) 
            Dim command As New OleDbCommand("INSERT into Links([id], parentId,[Text]) values (@ID,@parentId,@Text)", con) 
            command.Parameters.AddWithValue("ID", i.ToString()) 
            If parentId > -1 Then 
                command.Parameters.AddWithValue("parentId", parentId) 
            Else 
                command.Parameters.AddWithValue("parentId", System.DBNull.Value) 
            End If 
            command.Parameters.AddWithValue("Text", node.Text) 
            command.ExecuteNonQuery() 
        Next i 
        con.Close() 
    End Sub