Scrolling within datagrid

Question

Scrolling within datagrid I have a datagrid with its DataSource set to a dataset. The first time the user clicks on the button "show" 25 records are read. Now I need the following functionality: If the user scrolls down and the last record is reached, the next 25 records should be read. This is how I tried to do it: --------------------------------------------------------------------------- Private Sub grdDataGrid_Scroll(...) Handles grdDataGrid.Scroll Dim intShowAnzahl As Integer Try intShowAnzahl = dgcTopLeftVisibleCell.RowNumber + Me.grdDataGrid.VisibleRowCount If intShowAnzahl = intSatzAnzahl Then DataGridLoadNext() End If Catch ex As Exception ErrorMessage(...) End Try End Sub Private Sub DataGridLoadNext(Optional ByVal blnSetPoint As Boolean = False) Dim intNewAnz As Integer Dim intAktAnz As Integer Try If mblnFirst Then mblnFirst = False DataGridLoad() Else If intSatzAnzahl > 0 And intSatzAnzahl < objIBS_Query.lngMaxReadRecord Then blnSatzAnzahlEnde = True End If If blnSatzAnzahlEnde = False Then Me.Cursor = Windows.Forms.Cursors.WaitCursor intAktAnz = Me.BindingContext(Me.DseDataSetPatient1, "KHSPET0").Count intSatzAnzahl = intAktAnz objIBS_Query.DataAdapterFillWaiting(objIBS_Query.dadDataAdapterPatient, Me.DseDataSetPatient1, intSatzAnzahl, CInt(objIBS_Query.lngMaxReadRecord), "KHSPET0") DataGridFormat() If blnSetPoint = True Then If Me.grdDataGrid.RowCount > 0 Then 'hb130103 poiPointInCell00 = New Point(Me.grdDataGrid.GetCellBounds(0, 0).X + 4, Me.grdDataGrid.GetCellBounds(0, 0).Y + 4) End If End If intNewAnz = Me.BindingContext(Me.DseDataSetPatient1, "KHSPET0").Count If intAktAnz = intNewAnz Then blnSatzAnzahlEnde = True End If If intSatzAnzahl > intNewAnz Then blnSatzAnzahlEnde = True End If intSatzAnzahl = intNewAnz Me.Cursor = Windows.Forms.Cursors.Default Me.grdDataGrid.Refresh() End If End If Catch ex As Exception ErrorMessage(...) Finally End Try End Sub ------------------------------------------------------------------------- Sometimes this works fine. But sometimes it seems that the scroll event is fired again and again. Or in some other cases I only get an hourglass and nothing happens. Any idea what I may have forgotten?