Thread: the handle is invalid

hmm...yes i belive it is.

the "Owner" property is used for garbage disposal in BCB; but that's WAAAY up in the inheritance tree, so anything used in that function should be totally initialized at that point.

anyway, i changed it to memo=new TLabel, and it still occurred.

i wrapped all the new systemMessage statements with try/catch blocks, where the catch just retries to instatntiate the message, and it's working pretty well. i've gotten a lot of messages displayed with no problems.

here's the complete code. if someone sees something, please let me know!

Code:

//---------------------------------------------------------------------------

#ifndef SystemMessageScreenH
#define SystemMessageScreenH
//---------------------------------------------------------------------------
#include <SysUtils.hpp>
#include <Classes.hpp>
#include <Controls.hpp>
#include <Forms.hpp>
#include <ComCtrls.hpp>
//---------------------------------------------------------------------------
class TSystemMessageScreen;
class systemMessage : public TPanel
{
        protected:
                TLabel *memo;
                bool READ;
                TSystemMessageScreen *owner;
                String __fastcall gettime()
                {
                        String timeString;
                        TDateTime timeStamp = Now();
                        DateTimeToString(timeString,"yyyy-mm-dd hh:nn:ss.zz",timeStamp);
                        return timeString;
                }

                __property String timeStamp={read=gettime};
        public:
                __property bool read={read=READ};
                __fastcall systemMessage(TSystemMessageScreen *Owner,String msg);
};

class urgentMessage : public systemMessage
{
        protected:
                virtual void __fastcall acknowledgeClick(TObject *Sender);
        public:
                __fastcall urgentMessage(TSystemMessageScreen *Owner,String msg);
};

class warningMessage : public urgentMessage
{
        public:
                __fastcall warningMessage(TSystemMessageScreen *Owner,String msg);
};

class alarmMessage : public urgentMessage
{
        public:
                __fastcall alarmMessage(TSystemMessageScreen *Owner,String msg);
};

class PACKAGE TSystemMessageScreen : public TScrollBox
{
        private:
                DynamicArray<systemMessage *>messages;
                unsigned int UNREAD;
        protected:
        public:
                __fastcall TSystemMessageScreen(TComponent* Owner);

                __property unsigned int unread={read=UNREAD};

                void __fastcall ShowMessage(String msg);
                void __fastcall ShowWarning(String msg);
                void __fastcall ShowAlarm(String msg);                                
                void __fastcall setAcknowledged(systemMessage *msg);

        __published:
};
//---------------------------------------------------------------------------
#endif

Code:

//---------------------------------------------------------------------------

#include <vcl.h>

#pragma hdrstop

#include "SystemMessageScreen.h"
#pragma package(smart_init)
//---------------------------------------------------------------------------
// ValidCtrCheck is used to assure that the components created do not have
// any pure virtual functions.
//

static inline void ValidCtrCheck(TSystemMessageScreen *)
{
        new TSystemMessageScreen(NULL);
}
//---------------------------------------------------------------------------
__fastcall TSystemMessageScreen::TSystemMessageScreen(TComponent* Owner)
        : TScrollBox(Owner),
        UNREAD(0)
{
        AutoScroll = true;
}
//---------------------------------------------------------------------------
namespace Systemmessagescreen
{
        void __fastcall PACKAGE Register()
        {
                 TComponentClass classes[1] = {__classid(TSystemMessageScreen)};
                 RegisterComponents("custom", classes, 0);
        }
}
//---------------------------------------------------------------------------


void __fastcall TSystemMessageScreen::ShowMessage(String msg)
{
        try
        {
                systemMessage *m = new systemMessage(this,msg);
                m->Align = alTop;
                messages.Length++;
                messages[messages.High]=m;

        }
        catch(...)
        {
                ShowMessage(msg);        
        }
}

void __fastcall TSystemMessageScreen::setAcknowledged(systemMessage *s)
{
        UNREAD--;
}


void __fastcall TSystemMessageScreen::ShowWarning(String msg)
{
        try
        {
                systemMessage *m = new warningMessage(this,msg);
                m->Align = alTop;
                messages.Length++;
                messages[messages.High]=m;
                UNREAD++;

        }
        catch(...)
        {
                ShowWarning(msg);
        }
}

void __fastcall TSystemMessageScreen::ShowAlarm(String msg)
{
        try
        {
                systemMessage *m = new alarmMessage(this,msg);
                m->Align = alTop;
                messages.Length++;
                messages[messages.High]=m;
                UNREAD++;

        }
        catch(...)
        {
                ShowAlarm(msg);
        }
}

__fastcall systemMessage::systemMessage(TSystemMessageScreen *Owner,String msg) :
        TPanel(Owner),
        owner(Owner)
{
        try
        {
                memo=new TLabel(this);
                msg = timeStamp+": "+msg;

                Width = Owner->Width-1;

                Parent = Owner;
                Align = alTop;
                Height = 64;

                int numchars = Width/Canvas->TextWidth("0");

                TSysCharSet bchars;
                bchars << '.' << '-' << ' ';
                msg = WrapText(msg, "\n", bchars, numchars);

                memo->Transparent = true;
                memo->Parent = this;
                memo->Align = alTop;
                memo->Height = Height-1;
                memo->Caption = msg;

        }
        catch(...){}

}

void __fastcall urgentMessage::acknowledgeClick(TObject *Sender)
{
        READ = true;
        Color = clWhite;
        owner->setAcknowledged(this);
}

__fastcall urgentMessage::urgentMessage(TSystemMessageScreen *Owner,String msg) :
         systemMessage(Owner,msg)
{
        memo->OnClick= acknowledgeClick;
        OnClick= acknowledgeClick;
}


__fastcall warningMessage::warningMessage(TSystemMessageScreen *Owner,String msg) :
         urgentMessage(Owner,msg)
{
        Color= clYellow;
}


__fastcall alarmMessage::alarmMessage(TSystemMessageScreen *Owner,String msg) :
        urgentMessage(Owner,msg)
{
        Color= clRed;
}

alright, well, i'm positive i've gotten it now.

it was totally coincidence; it had nothing to do with this message system.

it was a threading conflict, trying to draw on a bitmap.

http://www.forumammo.com/cpg/albums/...o-facepalm.jpg