my smallest window prog

I was playing with the code to make it, trimmest window
programm and i came up with this.

good for beginners(atleast it creates a window for u)hehe

it creates a window and it works.

however if i change anycode in it , even a caption, it will
not compile a 2nd time.and it will give me error:

can not open debug.exe.

now if i go back and recode it as original, it still gives me
the same error. do you know why?im not exactly sure.

here is the code:

Code:

---


/*------------------------------------------------------------
 
                Sia k
  ------------------------------------------------------------*/

#include <windows.h>

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

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
                    PSTR szCmdLine, int iCmdShow)
{
    HWND        hwnd ;
    MSG          msg ;
    WNDCLASSEX    wndclass ;
    wndclass.cbSize        = sizeof(wndclass);
    wndclass.style        = CS_HREDRAW | CS_VREDRAW | CS_OWNDC ;
    wndclass.lpfnWndProc  = WndProc ;
    wndclass.cbClsExtra    = 0 ;
    wndclass.cbWndExtra    = 0 ;
    wndclass.hInstance    = hInstance ;
    wndclass.hIcon        = LoadIcon (NULL, IDI_APPLICATION);
    wndclass.hCursor      = LoadCursor (NULL, IDC_ARROW) ;
    wndclass.hbrBackground = (HBRUSH) GetStockObject(WHITE_BRUSH);
    wndclass.lpszMenuName  = NULL ;
    wndclass.lpszClassName = TEXT("hello") ;
    wndclass.hIconSm      = LoadIcon(NULL, IDI_APPLICATION);

    RegisterClassEx(&wndclass);
   
     
    hwnd = CreateWindow (TEXT("hello"), TEXT (" Hello"), WS_OVERLAPPEDWINDOW,               
            CW_USEDEFAULT,CW_USEDEFAULT, CW_USEDEFAULT,CW_USEDEFAULT, NULL,               
            NULL, hInstance,  NULL) ;                   
                                   
                                   
    ShowWindow (hwnd, iCmdShow) ;
    UpdateWindow (hwnd) ;
   
    while (GetMessage (&msg, NULL, 0, 0))
    {
          TranslateMessage (&msg) ;
          DispatchMessage (&msg) ;
    }
    return msg.wParam ;
}

LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
        return DefWindowProc (hwnd, message, wParam, lParam) ;
}

---

I suspect it can't recompile it because it cannot open the module because the module has not exited. Change your WindProc to process WM_DESTROY, something like this...

Code:

---

    switch(message)
    {
    case WM_DESTROY:
        PostQuitMessage(0);
        return 0;

    default:
        return DefWindowProc(hWnd,
                            message,
                            wParam,
                            lParam);
    }

---

Ya , i get you adrian. but the thing is i can recompile the
code as many times as i want .and it will show the window
and you can terminate it.

but as soon as you make any changes like:

window caption = "hello world"

and change it to:

window caption = "helo"

it wont recompile. and worse if u retype it as original
it keeps giving you the same error msg.

i am not sure. is it like a one time object window
that you cant change its attributes.

if you get the time can anyone try to recompile this
code?


*note; credit to adrians msg .later when i wanted to delete
the workspace for this program , windows wouldnt let me
by saying,

"you cant delete this file while its being used by another
application"

eventhough i had closed both the program window and VC++
window prior to this. and no other program was using it.

Perhaps the IDE realizes that nothing has changed, doesn't do a full recompile, and simply allows you to run the same executable without modification. However, once you change the contents of the file, the IDE realizes that it must recompile the entire project. It tries to write to the .exe, but fails since the old program is still running. Even if you change the code back to the original, the IDE senses that something has changed, attempts to recompile, and you run into the same error. Handling WM_DESTROY is most likely the solution.

>>> Ya , i get you adrian. but the thing is i can recompile the
code as many times as i want .and it will show the window
and you can terminate it.


If you have not changed anything between the last compilation and now, VC does not recompile it. Why should it, it is the same.

If I get a minute I'll have a look at it, but I'm pretty sure the problem is what we've already discussed.

<<If you have not changed anything between the last compilation and now, VC does not recompile it. Why should it, it is the same>>

Ok that says it all.thx

-----------------------------------------------------------------------------
while we are at the subject.
I have another program in win API->opengl that executes
fullscreen mode.and has the exact same problem.
I processed WM_KEYDOWN (VK_ESCAPE) to close the program.

yet after i terminate the fullscreen window , when i check
the task manager it will show the program process as still
running and (to rebuil) VC++ will give me the same error msg.

"cant open debug.exe"

i cant think of any reason why. i realy cant.

do you c the problem?

Code:

---



#define WIN32_LEAN_AND_MEAN
#pragma comment(lib, "opengl32.lib")
#pragma comment(lib, "glu32.lib")
#pragma comment(lib, "glaux.lib")
#pragma comment(linker, "/subsystem:windows")






#include <windows.h>
#include <gl/gl.h>
#include <gl/glu.h>
#include <gl/glaux.h>

float angle = 0.0f;


HDC g_HDC;
BOOL fullScreen = FALSE;
static char szAppName[] = TEXT ("Hello ") ;
HINSTANCE hInstance;
void SetupPixelFormat(HDC hdc)
{
int npixelformat;

static PIXELFORMATDESCRIPTOR pfd = {
        sizeof(PIXELFORMATDESCRIPTOR),
                1,
                PFD_DRAW_TO_WINDOW |
                PFD_SUPPORT_OPENGL |
                PFD_DOUBLEBUFFER,
                PFD_TYPE_RGBA,
                32,
                0, 0, 0, 0, 0, 0,
                0,
                0,
                0,
                0, 0, 0, 0,
                16,
                0,
                0,
                PFD_MAIN_PLANE,
                0,
                0, 0, 0,};
       
       
        npixelformat = ChoosePixelFormat(hdc, &pfd);
        SetPixelFormat(hdc, npixelformat, &pfd);
        }
LRESULT  CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam);

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
                    PSTR szCmdLine, int iCmdShow)
{


GLushort StipplePattern = 0xF000;
GLboolean b;       
       
       
   
          BOOL  done;
    HWND        hwnd ;
    MSG          msg ;
    WNDCLASSEX    wndclass ;
//--------------------------------
DWORD          dwExStyle;                               
        DWORD          dwStyle;                                       
        RECT          windowRect;

        // temp var's
        int width = 800;
        int height = 600;
        int bits = 32;

        fullScreen = TRUE;

        windowRect.left=(long)0;                                       
        windowRect.right=(long)width;               
        windowRect.top=(long)0;                                       
        windowRect.bottom=(long)height;                                       
//--------------------------------------------

    wndclass.cbSize        = sizeof(WNDCLASSEX);
    wndclass.style        = CS_HREDRAW | CS_VREDRAW ;
    wndclass.lpfnWndProc  = WndProc ;
    wndclass.cbClsExtra    = 0 ;
    wndclass.cbWndExtra    = 0 ;
    wndclass.hInstance    = hInstance ;
    wndclass.hIcon        = LoadIcon (NULL, IDI_APPLICATION);
    wndclass.hCursor      = LoadCursor (NULL, IDC_ARROW) ;
    wndclass.hbrBackground = NULL;
    wndclass.lpszMenuName  = NULL ;
    wndclass.lpszClassName = szAppName ;
    wndclass.hIconSm      = LoadIcon(NULL, IDI_APPLICATION);

    RegisterClassEx(&wndclass);

//------------------------------------------------------------       
        if (fullScreen)                                       
        {
                DEVMODE dmScreenSettings;               
                memset(&dmScreenSettings,0,sizeof(dmScreenSettings));
                dmScreenSettings.dmSize = sizeof(dmScreenSettings);       
                dmScreenSettings.dmPelsWidth = width;                       
                dmScreenSettings.dmPelsHeight = height;                       
                dmScreenSettings.dmBitsPerPel = bits;       
                dmScreenSettings.dmFields=DM_BITSPERPEL|DM_PELSWIDTH|DM_PELSHEIGHT;

               
                if (ChangeDisplaySettings(&dmScreenSettings, CDS_FULLSCREEN) != DISP_CHANGE_SUCCESSFUL)
                {
                        // setting display mode failed, switch to windowed
                        MessageBox(NULL, "Display mode failed", NULL, MB_OK);
                        fullScreen=FALSE;       
                }
        }

        if (fullScreen)                                                       
        {
                dwExStyle=WS_EX_APPWINDOW;                               
                dwStyle=WS_POPUP;                                       
                ShowCursor(FALSE);       
        }
        else
        {
                dwExStyle=WS_EX_APPWINDOW | WS_EX_WINDOWEDGE;                       
                dwStyle=WS_OVERLAPPEDWINDOW;                                       
        }

        AdjustWindowRectEx(&windowRect, dwStyle, FALSE, dwExStyle);                // Adjust Window To True Requested Size
//------------------------------------------------------------------------------------------------

hwnd = CreateWindowEx(dwExStyle,                                                                        // extended style
                                                  szAppName,                                                        // class name
                                                  "hello sara",                                      // app name
                                                  dwStyle | WS_CLIPCHILDREN |
                                                  WS_CLIPSIBLINGS,
                                                  0, 0,                                                               
                                                  windowRect.right - windowRect.left,
                                                  windowRect.bottom - windowRect.top,
                                                  NULL,                                                               
                                                  NULL,                                                       
                                                  hInstance,                                               
                                                  NULL);       


              if(!hwnd)
                return 0; 
   
    ShowWindow (hwnd, iCmdShow) ;
    UpdateWindow (hwnd) ;
    SetFocus(hwnd);
    done = FALSE;

        while(!done)
        {
                PeekMessage(&msg, hwnd, 0, 0, PM_REMOVE);
                if(msg.message == WM_QUIT)
                {
                        done  = TRUE;
                        break;

                }
                else
                {

TranslateMessage(&msg);
        DispatchMessage(&msg);


        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
        glLoadIdentity();
        angle = angle + 0.7f;

        if(angle >= 360.0f)
    angle = 0.0f;
        glTranslatef(0.0f, 0.0f, -5.0f);

    glColor3f(1.0f, 0.0f, 1.0f);
       
        glPolygonMode(GL_FRONT, GL_LINE);
    glBegin(GL_TRIANGLES);
glEdgeFlag(GL_TRUE);
        glVertex3f(0.0f, 1.0f, 0.0f);
glEdgeFlag(GL_FALSE);
  glVertex3f(-1.0f, 0.0f, 0.0f);
glEdgeFlag(GL_TRUE);
  glVertex3f(1.0f, 0.0f, 0.0f);
   
 

                       
       
        glVertex3f(0.0f, -1.0f, 0.0f);
glEdgeFlag(GL_FALSE);
    glVertex3f(1.0f, 0.0f, 0.0f);
glEdgeFlag(GL_TRUE);   
    glVertex3f(-1.0f, 0.0f, 0.0f);
       
        glEnd();

 
        SwapBuffers(g_HDC);

       
                }
       
       
        }


   
               
               
        return  msg.wParam;
}
LRESULT  CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
        static HGLRC hRC;
        static HDC hdc;
        char  hello[] = "HELLO SARA";
        int width, height;
 

        switch(message){

        case WM_CREATE:

                hdc = GetDC(hwnd);
                g_HDC = hdc;

                SetupPixelFormat(hdc);

                hRC = wglCreateContext(hdc);
        wglMakeCurrent(hdc ,hRC);


                return 0;
                break;

        case WM_KEYDOWN:
                if(wParam == VK_ESCAPE)

          SendMessage(hwnd, WM_CLOSE, 0, 0);
            return 0;
                break;

        case WM_SIZE:
                height = HIWORD (lParam);
                width  = LOWORD (lParam);
                if(height == 0)
                {
                        height = 1;
                }

                glViewport(0, 0, width, height);
                glMatrixMode(GL_PROJECTION);
                glLoadIdentity();
                gluPerspective(45.0f, (GLfloat)width / (GLfloat)height, 1.0f, 1000.0f);
                glMatrixMode(GL_MODELVIEW);
                glLoadIdentity();
                return 0;
                break;
    case WM_DESTROY:
                                                                           
       
                wglMakeCurrent(hdc, NULL);
                wglDeleteContext(hRC);
      if (fullScreen)
        {
                ChangeDisplaySettings(NULL,0);                       
                ShowCursor(TRUE);                                               
        }
        UnregisterClass(szAppName, hInstance);       
                PostQuitMessage(0);
               
                break;
        default:

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

---

Try adding a return 0; after your call to PostQuitMessage(). You need to be a bit careful the way you have it now. If you don't return from each message handler, you are then passing the message off to the default processor.

I don't have OpenGL so I can't try compiling this.

I added "return 0".

program still running after termination.:confused:

Take PostQuitMessage(0); out of WM_DESTROY and instead handle it inside of WM_CLOSE, use DestroyWindow(hWnd) in WM_DESTROY

Thx.
but no luck , process still running.

Are you sure? I copied your code and compiled it with the changes i suggested and the process ended when i closed the program. You sure theres not more code you have?

Excellent !

thx xds4lx.

i missed processing WM_DESTROY at first try.after your
2nd thread(push in the butt) i checked back & u r right.

but how come?

WM_DESTROY-->WM_QUIT-->postquitMessage(0);
should have done the job in original code.yet yours works.
:rolleyes:

Code:

---


 case WM_CLOSE:
                                                                           
            wglMakeCurrent(hdc, NULL);
                wglDeleteContext(hRC);
      if (fullScreen)
          {
                ChangeDisplaySettings(NULL,0);                       
                ShowCursor(TRUE);                                               
          }
            UnregisterClass(szAppName, hInstance);

                       
                PostQuitMessage(0);
                return 0;
                break;

        case WM_DESTROY:
                DestroyWindow(hwnd);
                return 0;
                break;

---

doesnt PostQuitMessage(0); post a WM_QUIT message in the message queue..which then returns 0 in the message loop which causes to exit out of the message loop...

in the messageloop it gets messages..translate the message (keyboard) and dispatchmessage(&msg) which calls windows to call the Window Procedure...only when the while loop doesnt return a 0 value...a WM_QUIT returns 0...so once the WM_QUIT message is received it exits out of the loop...and therefore at the end, ends program execution