🚀 go-pugleaf

"pera" <picka2@gmx.net> wrote in message
news:3e8dcd32$1@newsgroups.borland.com...

> void __fastcall TForm1::MyOnMessage(MSG& Msg, bool& Handled)

That suggests you're using the TApplication::OnMessage event.  If so, then
that is not the correct place to intercept the message in this situation.
As stated earlier, you need to subclass the ListView *directly*, and then
intercept WM_NOTIFY, not WM_LBUTTONDBLCLK.  A ListView control has a very
specific notification that is triggered when double-clicking on the dividers
of the header control.

This is a snippet of code I use in my own project:

    TWndMethod OldListViewProc;

    __fastcall TForm1::TForm1(TComponent *Owner)
        : TForm(Owner)
    {
        OldListViewProc = ListView1->WindowProc;
        ListView1->WindowProc = ListViewWindowProc;
    }

    void __fastcall TForm1::ListViewWindowProc(TMessage &Msg)
    {
        if( Msg.Msg == WM_NOTIFY )
        {
            const NMHDR *pnmh = (NMHDR*)Msg.LParam;
            if((pnmh->code == HDN_BEGINTRACKA) || (pnmh->code ==
HDN_BEGINTRACKW) ||
                (pnmh->code == HDN_DIVIDERDBLCLICKA) || (pnmh->code ==
HDN_DIVIDERDBLCLICKW))
            {
                // do something

                // if you want to swallow the message from being handled any
further:
                if( swallow the message )
                {
                    Msg.Result = TRUE;
                    return;
                }
            }
        }

        OldListViewProc(Msg);
    }


Gambit