I know that this is an argument already discussed here... but I cannot find the solution...
so... that's my problem:
I have a grid with column generated dinamically from DB in the page_load event (and here there's no problem...I see the columns)
after that, the user have to click a button and get data from DB, but after databind my grid is always empty!
here my code
:

markup code

<ext:Button ID="ButtonCerca" runat="server" Text="Submit">
                                        <AjaxEvents>
                                        <Click OnEvent="ButtonCerca_Click"></Click>
                                        </AjaxEvents>
                                        </ext:Button>

  <ext:Store ID="StoreGriglia" runat="server">
        <Reader>
            <ext:JsonReader ReaderID="RIGA_ID">
                <Fields>
                    <ext:RecordField Name="RIGA_ID">
                    </ext:RecordField>
                </Fields>
            </ext:JsonReader>
        </Reader>
    </ext:Store>

<ext:GridPanel runat="server" ID="Griglia" StoreID="StoreGriglia">
</ext:GridPanel>
vb.code
Protected Sub ButtonCerca_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles ButtonCerca.Click
        
        Dim SQL, SQL_FIELDS As String

        '### Here i get from session the structure of my Datatable/Grid
        Dim Vista As ClVista = Session(costanti.Utente.VISTA_CORRENTE)
        Dim ElencoCampi As List(Of ORM.Ff3dPcVisteStruct) = Vista.VistaStruct

        SQL = "SELECT "
        SQL_FIELDS = ""

        '#########   fields list
        For Each Campo As ORM.Ff3dPcVisteStruct In ElencoCampi

            If SQL_FIELDS <> "" Then SQL_FIELDS += ", "
            SQL_FIELDS += Campo.Campo

            '### Add field to store
            StoreGriglia.Reader(0).Fields.Add(Campo.Campo)
        Next

        SQL = SQL &amp; SQL_FIELDS &amp; " FROM " &amp; Vista.Vista.Vista &amp; " WHERE rownum<100"

        Dim cn As New Connessione.connessione(Vista.Vista.Istanza)
        Dim DT As New DataTable
        Try
            DT = cn.EseguiQueryDT(SQL)
        Catch ex As Exception

        End Try

        cn.Close()

'#### Here my DT has data inside

        StoreGriglia.DataSource = DT
        StoreGriglia.DataBind()
        Griglia.DataBind() '####i try  with this too!



    End Sub


at the end, i see just my grid with correct columns but without data...
Thanks