ASP.NET GridView Empty After Dynamic Fill From VB.NET

Question

I have an ASP.NET GridView that is not being populated with new rows from a VB.NET Fill. The most recent incarnation of the code I am working with is as follows:

Protected Sub uGV(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnQuery.Click 
    Dim rFm As DateTime = DateTime.Parse(calFrom.SelectedDate.Date.ToString)
    Dim rTo As DateTime = DateTime.Parse(calTo.SelectedDate.Date.ToString)
    Dim oleUpConnString As String = ConfigurationManager.ConnectionStrings("OLEDBConnectionStringtoSQL").ConnectionString
    Dim oleUpConn As New OleDbConnection()
    oleUpConn.ConnectionString = oleUpConnString
    oleUpConn.Open()
    Dim vUp As New OleDbDataAdapter()
    Dim upCmd As String = "SELECT * FROM mail WHERE (date BETWEEN '07/02/2013' AND '07/04/2013')"
    Dim dsUp As New DataSet()
    Dim dt As New DataTable("Table1")
    Dim upCmdEx As New OleDbCommand(upCmd, oleUpConn)
    With upCmdEx.Parameters
        .AddWithValue("?", rFm)
        .AddWithValue("?", rTo)
    End With
    Try
        vUp.SelectCommand = upCmdEx
    Catch ex As Exception
        MsgBox("The select command failed")
    End Try
    Try
        Me.GridView2.DataSource = dsUp.Tables(0)
        vUp.Fill(dsUp)
    Catch ex As Exception
        MsgBox("Filling the dataset failed")
    End Try
    Me.GridView2.DataSource = dsUp
    'Me.GridView2.DataBind()
    oleUpConn.Close()
End Sub

I have spent several hours on this without a resolution, so if someone could identify what I have missed it would be greatly appreciated.

EDIT - GridView is coded as follows:

<asp:GridView ID="GridView2" runat="server" AutoGenerateColumns="True" 
                    BackColor="White"  CaptionAlign="Top" 
                    CellPadding="4" ForeColor="#333333" 
                    GridLines="None" Caption="Surveys Completed">
                    <RowStyle BackColor="#EFF3FB" />
                    <FooterStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />
                    <PagerStyle BackColor="#2461BF" ForeColor="White" HorizontalAlign="Center" />
                    <SelectedRowStyle BackColor="#D1DDF1" Font-Bold="True" ForeColor="#333333" />
                    <HeaderStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />
                    <EditRowStyle BackColor="#2461BF" />
                    <AlternatingRowStyle BackColor="White" />
                </asp:GridView>

Answer 1

After extensive time spent on this, here is the final incarnation of the code behind for a Dynamic View feature for a GridView that will update in real-time with no page refresh required.

Protected Sub uGV(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnQuery.Click 
    Dim rFm As String = String.Empty
    Dim rTo As String = String.Empty
    rFm = calFrom.SelectedDate.Date.ToString
    rTo = calTo.SelectedDate.Date.ToString
    Dim oleUpConn As OleDbConnection = New OleDbConnection(ConfigurationManager.ConnectionStrings("OLEDBConnectionStringtoSQL").ConnectionString)
    Dim vUp As OleDbDataAdapter = New OleDbDataAdapter
    Dim selectSQL As String = "SELECT * FROM mail WHERE (date BETWEEN ? AND ?)"
    Dim upCmdEx As OleDbCommand = New OleDbCommand(selectSQL, oleUpConn)
    vUp.SelectCommand = upCmdEx
    upCmdEx.Parameters.AddWithValue("@FROMDATE", rFm)
    upCmdEx.Parameters.AddWithValue("@TODATE", rTo)
    Dim dsUp As DataSet = New DataSet
    vUp.Fill(dsUp, "DynamicView")
    If dsUp.Tables("DynamicView").Rows.Count > 0 Then
        GridView2.DataSource = dsUp.Tables("DynamicView")
        GridView2.DataBind()
    Else
        MsgBox("Nothing to display for the selected date range.  Please select a new date range and try again.")
        Exit Sub
    End If
End Sub

Answer 2

Without seeing your code, then I am going to guess that you either have not set AutoGenerateColumns attribute of the GridView to "True" or you have not defined Columns within the structure of your GridView.

To have the GridView automatically display all the columns (along with names) from the data source, then do the following:

<asp:GridView id="GridView2" runat="server" AutoGenerateColumns="True" />

To have more control over which columns you want displayed and/or what header names the columns have, then do this:

<asp:GridView id="GridView2" runat="server">
    <Columns>
        <asp:boundfield datafield="CustomerID" headertext="Customer ID" />
        <asp:boundfield datafield="CompanyName" headertext="Company Name"/>
        <asp:boundfield datafield="Address" headertext="Address"/>
        <asp:boundfield datafield="City" headertext="City"/>
        <asp:boundfield datafield="PostalCode" headertext="Postal Code"/>
        <asp:boundfield datafield="Country" headertext="Country"/>
    </Columns>
</asp:GridView>

Note: Obviously the boundfields are made up in this example and you can match the names to your data fields.