Public Overrides Function GetDesignTimeHtml() As String 
   ' Component is the instance of the component or control that 
   ' this designer object is associated with. This property is  
   ' inherited from System.ComponentModel.ComponentDesigner.
   simpleControl = CType(Component, Simple)

   If simpleControl.Text.Length > 0 Then 
      Dim sw As New StringWriter()
      Dim tw As New HtmlTextWriter(sw)

      Dim placeholderLink As New HyperLink()

      ' Put simpleControl.Text into the link's Text.
      placeholderLink.Text = simpleControl.Text
      placeholderLink.NavigateUrl = simpleControl.Text
      placeholderLink.RenderControl(tw)

      Return sw.ToString()
   Else 
      Return GetEmptyDesignTimeHtml()
   End If 
End Function

public override string GetDesignTimeHtml()
{
    if (simpleControl.Text.Length > 0)
    {
        string spec = "<a href='{0}.aspx'>{0}</a>";
        return String.Format(spec, simpleControl.Text);
    }
    else 
        return GetEmptyDesignTimeHtml();
}