Threads in Builder 6

Question

Hi i have problem it stopped my progress

I need to starttimer 200seconds to 0 (countdown in caption) by click on button, i have 48 buttons which are timers On google i found some about threads but dunno how to use it

timer_01.cpp:

__fastcall timer_01::timer_01(bool CreateSuspended)
        : TThread(CreateSuspended)
{
}

void __fastcall timer_01::Execute(TButton* buton)
    {
            if(buton->Caption=="Flash"){
                for(int i=flash_time;i>0;i--){
                    buton->Caption=i;
                    Sleep(1000);
                };
            }
    }
    //---------------------------------------------------------------------------

and my button in main_program.cpp

    void __fastcall TForm1::Button4Click(TObject *Sender)
    {
            Execute(Button4);

}

and include in main_program.cpp

#include "timer_01.h"

my main_program.h constructor i added:

 void __fastcall Execute(TButton* buton);

Answer 1

Your code is the completely wrong way to use TThread. Try something more like this instead:

timer_01.h:

class timer_01 : public TThread
{
private:
    TButton *fButton;
    String fValue;
    String __fastcall GetButtonCaption();
    void __fastcall DoGetButtonCaption();
    void __fastcall SetButtonCaption(const String &AValue);
    void __fastcall DoSetButtonCaption();
protected:
    void __fastcall Execute();
public:
    __fastcall timer_01(TButton *AButton);
};

timer_01.cpp:

__fastcall timer_01::timer_01(TButton *AButton)
    : TThread(true), fButton(AButton)
{
    FreeOnTerminate = true;
}

void __fastcall timer_01::Execute()
{
    if (GetButtonCaption() == "Flash")
    {
        for(int i = flash_time; (i > 0) && (!Terminated); --i)
        {
            SetButtonCaption(i);
            if (!Terminated)
                Sleep(1000);
        }
    }
}

String __fastcall timer_01::GetButtonCaption()
{
    Synchronize(&DoGetButtonCaption);
    return fValue;
}

void __fastcall timer_01::DoGetButtonCaption()
{
    fValue = fButton->Caption;
}

void __fastcall timer_01::SetButtonCaption(const String &AValue)
{
    fValue = AValue;
    Synchronize(&DoSetButtonCaption);
}

void __fastcall timer_01::DoSetButtonCaption()
{
    fButton->Caption = fValue;
}

main_program.cpp

#include "timer_01.h"

timer_01 *timer = NULL;

void __fastcall TForm1::Button4Click(TObject *Sender)
{
    if (timer)
    {
        timer->Terminate();
        do
        {
            CheckSynchronize();
            Sleep(10);
        }
        while (timer);
    }

    timer = new timer_01(Button4);
    timer->OnTerminate = &TimerTerminated;
    timer->Resume();
}

void __fastcall TForm1::TimerTerminated(TObject *Sender)
{
    timer = NULL;
}

With that said, you don't really need a TThread for such a simple timer. A TTimer would work just as well:

void __fastcall TForm1::Button4Click(TObject *Sender)
{
    Timer1->Interval = 1000;
    Timer1->Tag = flash_time;
    Timer1->Enabled = true;
}

void __fastcall TForm1::Timer1Timer(TObject *Sender)
{
    if (Timer1->Tag > 0)
    {
        Button4->Caption = Timer1->Tag;
        Timer1->Tag = Timer1->Tag - 1;
    }
    else
        Timer1->Enabled = false;
}