I’m looking at an existing project, trying to make sense of something that VB.NET is doing or allowing:

    Protected Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        If Session("UserID") Is Nothing Then
            Response.Redirect("~/AccessDenied.aspx")
            Exit Sub
        End If

        ' Variables
        Dim oNotes As New VistaClaims.ClaimsInfo.NoteDB
        Dim DSNotes As New DataSet
        Dim dgNotes As DataGrid = dgNotes
        Dim oRecoveries As New VistaClaims.ClaimsInfo.RecoveryDB
        Dim oBills As New VistaClaims.ClaimsInfo.PaymentDB
        Dim oSubro As New VistaClaims.ClaimsInfo.SubroDB
        Dim DSRecoveries As New DataSet
        Dim DSBills As New DataSet
        Dim DSSubro As New DataSet
        'Dim dgBills As DataGrid = dgBills
        'Dim dgRecoveries As DataGrid = dgRecoveries

The issue I have is with the line Dim dgNotes As DataGrid = dgNotes.

I tried commenting it out, thinking it was defined on the ASP.NET WebForm, but it was not and I got errors.

I’ve done more C# development, and often VB.NET does things that I think should be illegal – but they work.

The code works. There is no error that I know of. I just happened to open this particular form on an old project today, and I thought I’d resolve the possible (likely, it seems to me) null reference exception.

What is that line of code doing? I don’t understand.