I would define an interface IIOEnable and have your subclassed controls implement that interface

then - excuse the syntax - vb and c# mixture

foreach ( Control ctrl in Me.Controls )
{
    IIOEnable ctrl1 = ctrl as IIOEnable ;
    if( ctrl1 != null )
         ctrl1.ioEnable(value);

}

>I have subclassed textboxes, panels and buttons. For each of those controls, I wrote an IOEnable method. I would like my (subclassed) form to execute these methods. I came up with something like this, which works, but am wondering if there is not a more generic approach to this, because now, each time I subclass a control I have to kind of "register" it here and in every container.
>

>For Each ctrl As Control In Me.Controls
>     If TypeOf ctrl Is txtBase Then
>         Dim ctrl1 As txtBase = ctrl
>         ctrl1.ioEnable(value)
>     End If
>     If TypeOf ctrl Is pnlBase Then
>         Dim ctrl1 As pnlBase = ctrl
>         ctrl1.ioEnable(value)
>     End If
>     If TypeOf ctrl Is btnBase Then
>         Dim ctrl1 As btnBase = ctrl
>         ctrl1.ioEnable(value)
>     End If
> Next
>

>
>In VFP this looked like this
>

>for each o in this.Controls
>        if !pemstatus(o,'IOEnable',5)
>            loop
>        endif
>        o.IOEnable()
>    endif
>endfor
>