Creating a count down text in window

Hi,

I'm trying to display text into my window. My idea is to create a count down that displays in the window, using a for loop. I'm using the sleep() function to control the time.

Basically I just want the text to be displayed in window as the count down decrements.

It's suppose to go like this:
count=3
count=2
count=1

Here's my code:

Code:

---

#include <windows.h>
#include <mmsystem.h>

LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;


LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
        HDC                hdc;
        RECT        rect;
        int count = 5;
        int i;

        switch (message){

                case WM_PAINT:
                        hdc = BeginPaint(hwnd, &ps);
                        for(i=0; i<5; i++)
                        {
                                count --;
                                Sleep(1000);//causes the main thread to sleep for 1 seconds - allowing another thread to run
                                TextOut(hdc, 20, 20,TEXT("count = &#37;d\n",count),12);
                        }

                       
                        EndPaint(hwnd, &ps);
                        return 0;

        }

        return DefWindowProc(hwnd, message, wParam, lParam);
}

---

what problems are you having? maybe try TextOut() too. And of course you know making it sleep for any amount of time means the program won't respond for that time right ;)

I tried with textOut, but it only displays "count = %d". But it doesn't show the count down.

Code:

---

#include <stdio.h>
.
.
.
char szTextOut[128] = {0};
.
.
.
  //TextOut(hdc, 20, 20,TEXT("count = %d\n",count),12);
  memset(szTextOut, 0, sizeof szTextOut);
  sprintf(szTextOut,"count = %d", count); 
 TextOut(hdc, 20, 20,szTextOut, strlen(szTextOut));

---

thanks for the help, but why does the text is displayed in another language?

Try using unicode.

How can I use unicode? Is there a special symbol I need to apply to my code?

Turn char to TCHAR, and add #define UNICODE.

I tried that but it didn't work

You did not state what your app actually diaplays. My guess it just the last number?

Your method will not work PROPERLY for a number of reasons as you want it to. Mainly due to the Sleep().



I would use a timer. Call SetTimer() in the WM_INITDIALOG. The timer will execute every time period (1000 ms) until you call KillTimer().

Have a static int in the callback (or member in C++). In the WM_TIMER increment the int and call for a paint with InvalidateRect() followed by UpdateWindow().

In the WM_PAINT draw the text to the screen.

Please note it MUST be a static variable.

Actualy, the callback varibles really should be global.

>> I tried that but it didn't work
Sorry, I thought when you said "another language" you really meant like English, French, Spanish, ect...

Also, "Last edited by vopo : Yesterday at 02:58 PM. Reason: so people won't steal my code, for temporary purposes".
No one is going to do that, especially if it's not working. ;)

Quote:

---

Originally Posted by Yarin

Actualy, the callback varibles really should be global.

---

Why use a global over a static local in this case?

If global, the variable would have more scope than required, can cause confusion (if a variable local to a function has the same name), makes the code harder to read and (in this case) will not improve performance.

IMO a static local is the right choice.

IMO globals should only be used as a last resort unless you can justify their use. Just like goto, global variables, can usually be avoided by better design.

Last resort? Globals never cause confusion.
I'll show you the simple concept:

Code:

---

int var = 4;
// here, var == 4
int main(void)
{
  int var = 3;
  // here, var == 3
  if(1)
  {
      int var = 2;
      // here, var == 2
  }
  return 0;
}

---

Further more, gotos can be freely used with no problems, so long as you know what your doing. This last resort stuff is bahh.

Quote:

---

Originally Posted by Yarin

Last resort? Globals never cause confusion.

---

What is your working expirience? 2 days?
Do not make statements based on the absence of real work expirience. Do not confuse others with your own errors...

In real world support of the programs with Globals vars - is a hell of the programmer

Quote:

---

Originally Posted by Yarin

Further more, gotos can be freely used with no problems.

---

As well as with a lot of problems.
So DO NOT use them until you 200% sure you need it.

You are yet to give a reason why a global is better than a static local, in this case.

I have justified my choice with a (IMO good) reason.

I suggest the OP look at our posts and join dates (and post counts) and decide for themselves whom to trust.

To the OP...

As I derailed oyur thread, here is some code illustrating what I mean.

Code:

---

//in resource.h or header
#define IDT_COUNTDOWN 40001 //past the numbers used by the IDE

//in callback
static UINT    uiTimer=0;
static int                iCountDown=5;

case WM_CREATE:
case WM_INITDIALOG:
        //create a timer
        uiTimer=SetTimer(hWnd,IDT_COUNTDOWN,1000,NULL);
        //TODO set return value
        break;
case WM_TIMER:
        if(wParam==uiTimer)//is it the count down timer?
        {
                iCountDown--;
                if(iCountDown<0)//if the count down is ended, kill the timer.
                        KillTimer(hWnd,uiTimer);
                InvalidateRect(hWnd,NULL,false);//redraw whole window
                UpdateWindow(hWnd);//post directly to the callback, not to the msg queues
        }
        //TODO set return value
        break;
case WM_PAINT:
        PAINTSTRUCT    PS;
        BeginPaint(hWnd,&PS);
        //draw text
        char    szBuf[MAX_PATH]={0};//init string empty
        if(iCountDown>=0)//choose what to display
                _snprintf(szBuf,MAX_PATH-1,"Count is %d.",iCountDown);
        else
                _snprintf(szBuf,MAX_PATH-1,"Countdown has ended.");//tell user countdown is over
        TextOut(PS.hdc,20,20,szBuf,lstrlen(szBuf));
        EndPaint(hWnd,&PS);
        //TODO set return value
        break;

---

thanks for the help.

I'll post my final code later

use sprintf() to put your text into a string, then use DrawText() to print it.

Never use Sleep() in the message loop, ever, ever, no not even then. If you need to trigger the update in the message loop, use a timer.

Code:

---

        akshar += sprintf((char*)&szString[akshar] , "  Count = %d\n" , Count );

        DrawText(hdc , (char*)&szString[0] , -1 , &Rect , DT_TOP | DT_LEFT );

---

>> You are yet to give a reason why a global is better than a static local, in this case.
>> I have justified my choice with a (IMO good) reason.
Okay, I see your point.

>> I suggest the OP look at our posts and join dates (and post counts) and decide for themselves whom to trust.
That makes no difference; It's not like we both joined the board when we first started programming. :rolleyes: