Autocompletar un combobox

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

        ComboBox1.AutoCompleteMode = AutoCompleteMode.Append

        ComboBox1.AutoCompleteSource = AutoCompleteSource.CustomSource

        Dim combData As New AutoCompleteStringCollection()

        getData(combData)

        ComboBox1.AutoCompleteCustomSource = combData

      End Sub

  Private Sub getData(ByVal dataCollection As AutoCompleteStringCollection)

        Dim connetionString As String = Nothing

        Dim connection As SqlConnection

        Dim command As SqlCommand

        Dim adapter As New SqlDataAdapter()

        Dim ds As New DataSet()

        connetionString = "Data Source=SERVIDOR;Initial Catalog=BD;User ID=USUARIO;password=CONTRASEÑA""

        Dim sql As String = "SELECT DISTINCT [CAMPO] FROM [TABLA]"

        connection = New SqlConnection(connetionString)

        Try

            connection.Open()

            command = New SqlCommand(sql, connection)

            adapter.SelectCommand = command

            adapter.Fill(ds)

            adapter.Dispose()

            command.Dispose()

            connection.Close()

            For Each row As DataRow In ds.Tables(0).Rows

                dataCollection.Add(row(0).ToString())

            Next

        Catch ex As Exception

            MessageBox.Show(ex.Message)

        End Try

    End Sub