what is wrong with my winmain

[jcylam]

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR szCmdLine, int iCmdShow)
{
	static TCHAR szAppName[] = TEXT ("Digital Clock");
	HWND		 hwnd;
	MSG			 msg;
	WNDCLASS	 wndclass;

	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	= (HBRUSH) GetStockObject (WHITE_BRUSH);
	wndclass.lpszMenuName	= NULL;
	wndclass.lpszMenuName	= szAppName;

	if (!RegisterClass (&wndclass))
	{
		MessageBox (NULL, TEXT ("Program doesn't register"), szAppName, MB_ICONERROR);
		return 0;
	}

	hwnd = CreateWindow (
						 szAppName,
						 TEXT ("Digital Clock"),
						 WS_OVERLAPPEDWINDOW,
						 200,
						 200,
						 500,
						 500,
						 NULL,
						 NULL,
						 hInstance,
						 NULL
						);

	ShowWindow (hwnd, iCmdShow);
	UpdateWindow (hwnd);

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

	return msg.wParam;
}

it compiles fine, but when trying to run the program, it crashes at registerclass saying something is wrong with hInstance.

thanks

[Lamblion]

You have two "wndclass.lpszMenuName"

One of them should be "wndclass.lpszClassName"

[freddie1]

Try using WNDCLASSEX and RegisterClassEx().

[freddie1]

Thatr's probably it Lamblion. I consider the lpfnWndProc and lpszClassName to be the two most critically important members, and always put them at top.

[jcylam]

thanks so much!!

[zippo]

THe problem actually is that wndclass is not initialized correctly. Some data might be invalid.
Just change the line

WNDCLASS wndclass;


to

WNDCLASS wndclass = {0};

cheers