Hello

I’m experience a problem with a combo at VB .NET.

I’m developing a window application and I’m using a combobox.

I’m populating the combo with a dataset. I set its ValueMenber and
DisplayMenber, and the selectedindex to -1. The dropdownstyle is set to
DropDown, but the problem persists whit DropDownList.
When I click in the button, it shows a message box whit theValueMenber and
DisplayMenber. Them I set again the selectindex to -1. The problem is that
the selectedIndex that the combo assume is 0, therefore it show its first
value.

This is the code that I use.

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MyBase.Load

       Dim objset As New DataSet
       Dim str1 As String
       objset = SP_Combo(strcon)
       'cb1.DataSource = objset.Tables("Destinos")
       cb1.DataSource = objset.Tables("Empregados")
       'cb1.DisplayMember = "nome"
       cb1.DisplayMember = "FirstName"
       cb1.SelectedIndex = -1
       Match = -1
       objset.Dispose()
       objset = Nothing

     
   End Sub

Public Function SP_Combo(ByVal strConn As String) As DataSet
       Dim a As String
       Dim objComm As New SqlCommand
       Dim objDataSet As New DataSet
       Dim ObjdataAd As New SqlDataAdapter
       Dim objConn As New SqlConnection(strConn)
       objConn.Open()
       With objComm
           .Connection = objConn
           .CommandType = CommandType.Text
           .CommandText = "Select EmployeeID, FirstName from Employees
order by FirstName"
           '.CommandType = CommandType.StoredProcedure
           '.CommandText = "SpNet_DestRecp"
           '.Parameters.Add(New SqlParameter("@Var_Onde",
"Combo")).Direction = ParameterDirection.Input
       End With
       ObjdataAd.SelectCommand = objComm
       'ObjdataAd.Fill(objDataSet, "Destinos")
       ObjdataAd.Fill(objDataSet, "Empregados")
       objComm.Dispose()
       objComm = Nothing
       ObjdataAd.Dispose()
       ObjdataAd = Nothing
       objConn.Close()
       objConn.Dispose()
       objConn = Nothing
       Return objDataSet
   End Function

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
       If Match <> -1 And cb1.SelectedIndex = -1 Then
           cb1.SelectedIndex = Match
           Match = -1
       End If

       If cb1.SelectedIndex <> -1 Then
           MsgBox("Numero: " & cb1.SelectedValue & " com o nome " &
cb1.GetItemText(cb1.SelectedItem))
           MsgBox("Indice: " & cb1.SelectedIndex)
       End If
       
       cb1.SelectedIndex = -1

   End Sub

To resolve this issue I populate the combo again. But this makes the
application slower.

There’s anyone who knows to resolve this little problem?

Thanks to all.

Ana Rita