[Solved] ASP.Net GridView Error: SelectedIndexChanged is not a member of

Please help when i add SelectedIndexChanged and rowcommand i get the error below

Server Error in '/' Application.
Compilation Error
Description: An error occurred during the compilation of a resource required to service this request. Please review the following specific error details and modify your source code appropriately.

Compiler Error Message: BC30456: 'Studentgrid_SelectedIndexChanged' is not a member of 'forms_casestudents_aspx'.

Source Error:


Line 87: <tr>
Line 88:     <td>
Line 89:         <asp:GridView ID="Studentgrid" runat="server"  ItemStyle-Width="Auto" AutoGenerateColumns="False" OnSelectedIndexChanged="Studentgrid_SelectedIndexChanged" OnRowCommand="Studentgrid_RowCommand" >
Line 90:             <Columns>
Line 91:                 <asp:ButtonField HeaderText="Edit Record" Text="Select" />


Source File: C:\Users\Makumbi\source\repos\INTERVIEWSVB\INTERVIEWSVB\Forms\Casestudents.aspx    Line: 89

Show Detailed Compiler Output:

Show Complete Compilation Source:

Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.8.4465.0 

Public Class Casestudents
    Inherits System.Web.UI.Page
    Dim conString As String = ConfigurationManager.ConnectionStrings("INTERVIEWSConnectionString").ConnectionString

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        If Not Me.IsPostBack Then
            Studentgrid.DataBind()
        End If
    End Sub
    Private Sub Studentgrid_SelectedIndexChanged(sender As Object, e As EventArgs) Handles Studentgrid.SelectedIndexChanged
        Try
            Dim index As Integer = Studentgrid.SelectedIndex
            Dim gvRow As GridViewRow = Studentgrid.Rows(index)
            Dim named As String = Studentgrid.SelectedRow.Cells(1).Text
            Dim namesd As String = Studentgrid.SelectedRow.Cells(2).Text
            Dim commandName As String = sender.ToString()

            If String.IsNullOrEmpty(Studentgrid.SelectedRow.Cells(8).Text.Trim().Replace(" ", String.Empty)) Then
                Response.Redirect(String.Format("~/Forms/casedata2.aspx?account={0}&Names={1}", named, namesd))
            Else
                Dim comments As String = Studentgrid.SelectedRow.Cells(8).Text
                Response.Redirect(String.Format("~/Forms/casedata2.aspx?account={0}&Names={1}&comment={2}", named, namesd, comments))

            End If
        Catch ex As Exception
        End Try
    End Sub

    Private Sub Studentgrid_RowCommand(sender As Object, e As GridViewCommandEventArgs) Handles Studentgrid.RowCommand
        If e.CommandName = "View Document" Then
            Dim named As String = Studentgrid.SelectedRow.Cells(1).Text
            Dim namesd As String = Studentgrid.SelectedRow.Cells(2).Text

            Response.Redirect(String.Format("~/Forms/docdetails.aspx?account={0}&Names={1}", named, namesd))
        End If
    End Sub

    Private Sub Studentgrid_SelectedIndexChanging(sender As Object, e As GridViewSelectEventArgs) Handles Studentgrid.SelectedIndexChanging

    End Sub
End Class