Custom Sorting in TreeView using C# and VB.Net in ASP.Net

Hi dnnyobi,

Check this example. Now please take its reference and correct your code.

HTML

<asp:TreeView ID="TreeView1" runat="server">
</asp:TreeView>

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        string[] characters = new string[] { "A", "B", "CH", "D", "E", "Ẹ", "F", "G", "GB", "GH", "GW", "H",
                                    "I", "Ị", "J", "K", "KP", "KW", "L", "M", "N", "NW", "NY", "Ṇ",
                                    "O", "Ọ", "P", "S", "Ṣ", "T", "U", "Ụ", "V", "W", "Y", "Z", "Ẓ"
                                };
        // Get the DataTable from Database.
        System.Data.DataTable dt = new System.Data.DataTable();
        dt.Columns.AddRange(new System.Data.DataColumn[] { new System.Data.DataColumn("Word", typeof(string)) });
        dt.Rows.Add("Abu");
        dt.Rows.Add("Ịjeoma");
        dt.Rows.Add("Baba");
        dt.Rows.Add("Chekube");
        dt.Rows.Add("Ṣeka");
        dt.Rows.Add("Daniel");
        dt.Rows.Add("Ụdu");
        dt.Rows.Add("Ego");
        dt.Rows.Add("Humpty");
        dt.Rows.Add("Ify");
        dt.Rows.Add("Ẹnuwa");
        dt.Rows.Add("Samuel");
        dt.Rows.Add("Ulo");
        List<string> newLists = new List<string>();
        foreach (string character in characters)
        {
            foreach (System.Data.DataRow dr in dt.Rows)
            {
                if (dr["Word"].ToString().StartsWith(character))
                {
                    if (!newLists.Contains(dr["Word"].ToString()))
                    {
                        newLists.Add(dr["Word"].ToString());
                        TreeView1.Nodes.Add(new TreeNode { Text = dr["Word"].ToString() });
                    }
                }
            }
        }
    }
}

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    If Not IsPostBack Then
        Dim characters As String() = New String() {"A", "B", "CH", "D", "E", "Ẹ", "F", "G", "GB", "GH", "GW", "H", "I", "Ị", _
                                                   "J", "K", "KP", "KW", "L", "M", "N", "NW", "NY", "Ṇ", "O", "Ọ", "P", "S", _
                                                   "Ṣ", "T", "U", "Ụ", "V", "W", "Y", "Z", "Ẓ"}
        ' Get the DataTable from Database.
        Dim dt As System.Data.DataTable = New System.Data.DataTable()
        dt.Columns.AddRange(New System.Data.DataColumn() {New System.Data.DataColumn("Word", GetType(String))})
        dt.Rows.Add("Abu")
        dt.Rows.Add("Ịjeoma")
        dt.Rows.Add("Baba")
        dt.Rows.Add("Chekube")
        dt.Rows.Add("Ṣeka")
        dt.Rows.Add("Daniel")
        dt.Rows.Add("Ụdu")
        dt.Rows.Add("Ego")
        dt.Rows.Add("Humpty")
        dt.Rows.Add("Ify")
        dt.Rows.Add("Ẹnuwa")
        dt.Rows.Add("Samuel")
        dt.Rows.Add("Ulo")
        Dim newLists As List(Of String) = New List(Of String)()
        For Each character As String In characters
            For Each dr As System.Data.DataRow In dt.Rows
                If dr("Word").ToString().StartsWith(character) Then
                    If Not newLists.Contains(dr("Word").ToString()) Then
                        newLists.Add(dr("Word").ToString())
                        TreeView1.Nodes.Add(New TreeNode With {.Text = dr("Word").ToString()})
                    End If
                End If
            Next
        Next
    End If
End Sub

Output 

Abu 

Baba

Daniel

Ego

Ẹnuwa

Humpty

Ify

Ịjeoma

Samuel

Ṣeka

Ulo

Ụdu