Public Class MyComboBox
    Inherits System.Windows.Forms.ComboBox

    Private _MyBgWorker As System.ComponentModel.BackgroundWorker

    Public Sub New()

        MyBase.New()

        Me._MyBgWorker = New System.ComponentModel.BackgroundWorker()
        AddHandler Me._MyBgWorker.DoWork, AddressOf _MyBgWorker_DoWork
        AddHandler Me._MyBgWorker.RunWorkerCompleted, AddressOf _MyBgWorker_RunWorkerCompleted

    End Sub

    Private Sub _MyBgWorker_DoWork(ByVal sender As Object, ByVal e As System.ComponentModel.DoWorkEventArgs)

        Dim Query As String = e.Argument.ToString()
        Dim Dati As New GestioneDati.InterfacciaDb()

        Dati.FillDt(Query)

        e.Result = Dati.Dt

    End Sub

    Private Sub _MyBgWorker_RunWorkerCompleted(ByVal sender As Object, ByVal e As System.ComponentModel.RunWorkerCompletedEventArgs)

        If Not e.Cancelled And e.Error Is Nothing Then

            Me.DataSource = e.Result

        End If

    End Sub

    Public Sub PopolaValori(ByVal Query As String)

        Me._MyBgWorker.RunWorkerAsync(Query)

    End Sub

End Class