'我想在TEXTBOX中输入东西.怎么能让在输入23***的时候,就可以把TEXTBOX下拉,在下面显示以前输入过的23开头的都显示在下面呢?

Private Sub TextBox1_KeyDown(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles TextBox1.KeyDown
        Dim firststring As String = 23
        If e.KeyCode = 13 Then
            Me.TextBox1.Text &= 23
        End If
    End Sub