Help pls - Create child windows

[adimisu]

Help pls. Am luat exemplul asta din MSDN care creaza o fereastra si in interiorul ei 3 ferestre copil. Problema e ca atunci cand il rulez imi omoara calculatorul si trebuie sa-l inchid din TaskManager. Ce nu fac bine?
[code]#include <windows.h>

#define ID_FIRSTCHILD 100
#define ID_SECONDCHILD 101
#define ID_THIRDCHILD 102

HINSTANCE ghInstance;

BOOL CALLBACK EnumChildProc(HWND hwndChild, LPARAM lParam)
{
LPRECT rcParent;
int i, idChild;

// Retrieve the child-window identifier. Use it to set the
// position of the child window.

idChild = GetWindowLong(hwndChild, GWL_ID);

if (idChild == ID_FIRSTCHILD)
i = 0;
else if (idChild == ID_SECONDCHILD)
i = 1;
else
i = 2;

// Size and position the child window.

rcParent = (LPRECT) lParam;
MoveWindow(hwndChild,
(rcParent->right / 3) * i,
0,
rcParent->right / 3,
rcParent->bottom,
TRUE);

// Make sure the child window is visible.

ShowWindow(hwndChild, SW_SHOW);

return TRUE;
}

LRESULT CALLBACK MainWndProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
RECT rcClient;
int i;
HWND hwnd1;

switch(uMsg)
{
case WM_CREATE: // creating main window

// Create three invisible child windows.

for (i = 0; i < 3; i++)
{
hwnd1 = CreateWindowEx(0,
TEXT("ChildWClass"),
TEXT("Bla Bla"),
WS_CHILD | WS_BORDER,
0, 0, 0, 0,
hwnd,
(HMENU) (int) (ID_FIRSTCHILD + i),
//NULL
ghInstance,
NULL);
//ShowWindow(hwnd1, SW_SHOW);
}

return 0;

case WM_SIZE: // main window changed size

// Get the dimensions of the main window's client
// area, and enumerate the child windows. Pass the
// dimensions to the child windows during enumeration.

GetClientRect(hwnd, &rcClient);
EnumChildWindows(hwnd, EnumChildProc, (LPARAM) &rcClient);
return 0;

// Process other messages.
}
return DefWindowProc(hwnd, uMsg, wParam, lParam);
}


int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd)
{
HWND hWnd;
MSG message;
WNDCLASSEX mywindow;

mywindow.cbClsExtra = 0;
mywindow.cbSize = sizeof(mywindow);
mywindow.cbWndExtra = 0;
mywindow.hbrBackground = GetStockObject(WHITE_BRUSH);
mywindow.hCursor = LoadCursor(NULL, IDC_ARROW);
mywindow.hIcon = LoadIcon(NULL, IDI_APPLICATION);
mywindow.hIconSm = NULL;
mywindow.lpfnWndProc = MainWndProc;
mywindow.hInstance = hInstance;
mywindow.lpszClassName = TEXT("ChildWClass");
mywindow.lpszMenuName = NULL;
mywindow.style = CS_HREDRAW | CS_VREDRAW;

RegisterClassEx(&mywindow);

hWnd = CreateWindowEx(0L,
TEXT("ChildWClass"),
TEXT("Bla bla"),
WS_OVERLAPPEDWINDOW | WS_HSCROLL | WS_VSCROLL,
CW_USEDEFAULT,
CW_USEDEFAULT,
CW_USEDEFAULT,
CW_USEDEFAULT,
NULL,
NULL,
hInstance,
NULL);

ghInstance = hInstance;

ShowWindow(hWnd, nShowCmd);
UpdateWindow(hWnd);

while(GetMessage(&message, NULL, 0, 0))
{
TranslateMessage(&message);
DispatchMessage(&message);
}

return(message.wParam);
}[/code]

[Smiley]

la prima vedere (n-am mai lucrat de mult cu API windows) folosesti aceeasi clasa si pentru fereastra principala si pentru ferestrele copil. din cauza ca ai pus pe WM_CREATE-ul ferestrei respective sa-ti creeze alte 3 ferestre, care folosesc aceeasi MainWndProc, fiecare din cele 3 ferestre incearca sa creeze alte 3 ferestre, care la randul lor fac fiecare inca 3 si asa ai obtinut un algoritm recursiv infinit.


Fie iti creezi o alta clasa de ferestre pentru copii fie gasesti alt mod de a le identifica, astfel incat in MainWndProc ferestrele copil sa nu mai incerce sa creeze si ele alte ferestre copil.

[Karg]

muta codul care creeaza cele 3 ferestre din WM_CREATE in WinMain, dupa ce creezi fereastra principala. din ceva motiv, CreateWindowEx pentru child windows trimite mesaj WM_CREATE care ajunge in acelasi loc, practic ai un soi de recursivitate.

apoi, adauga si asa ceva in MainWndProc, altfel iti ramine duda agatata in pom:
[code]
// Process other messages.
case WM_DESTROY:
PostQuitMessage (0); /* send a WM_QUIT to the message queue */
return 0;
[/code]

[DeceaseD]

chiar urasc metoda Microsoft de GUI development. Traiasca QT si niste baieti destepti care s-au gandit la SIGNALS & SLOTS.