Question

I derived a component from System.Windows.Forms.ScrollableControl and I have problems to add border property. I tried with CreateParams but without success, maybe I miss something?

Protected Overrides ReadOnly Property CreateParams() As System.Windows.Forms.CreateParams
    Get
        Dim params As CreateParams = MyBase.CreateParams
        params.Style = params.Style Or &H800000 ' Turn on WS_BORDER
        Return params
    End Get
End Property

 'disable scroll bars, this part also disables my border
Protected Overrides Sub DefWndProc(ByRef m As Message)
    If m.Msg <> 131 Then
        MyBase.DefWndProc(m)
    End If
End Sub

Answer 1

Looks like you want to have a border property of true/false:

Protected Overrides ReadOnly Property CreateParams() As CreateParams
  Get
    Dim params As CreateParams = MyBase.CreateParams
    If _Border Then
      params.Style = params.Style Or &H800000 ' Turn on WS_BORDER
    End If
    Return params
  End Get
End Property

Private _Border As Boolean = False

Property Border() As Boolean
  Get
    Return _Border
  End Get
  Set(ByVal value As Boolean)
    _Border = value
    Me.RecreateHandle()
    Me.Invalidate()
  End Set
End Property

Bob Powell has an article regarding that: Adding a standard border to a control