Yo I''ve created class glwindow and put inside a function: LRESULT CALLBACK WndProc( HWND, UINT, WPARAM, LPARAM ); My class has an object-member of type WNDCLASS, and while creating proper window i assign some things to its data-members. Everything goes ok until that line: wc.lpfnWndProc = ( WNDPROC ) WndProc; The error is: ''type cast'' : cannot convert from ''overloaded-function'' to ''WNDPROC'' None of the functions with this name in scope match the target type. When i changed WndProc to a normal global function everything went ok. What''s going on?? Please help!!

The WndProc function must be outside of the class definition. There are several articles on how this is done. Here is my implimentation:

LRESULT CALLBACK WndProc(HWND	hWnd,			// Handle For This Window						 UINT	uMsg,			// Message For This Window						 WPARAM	wParam,			// Additional Message Information						 LPARAM	lParam)			// Additional Message Information{	oglTopWindow *topWindow;		// This is the first msg that is received by WndProc		// Use it to save the CreateParam, which is the C++ class pointer		// into the userdata area of the HWND	if (uMsg == WM_NCCREATE) {			// Get pointer to window object passed as create param		topWindow = reinterpret_cast<oglTopWindow *>(((LPCREATESTRUCT)lParam)->lpCreateParams);			// Save the Win32 window handle in the window object		topWindow->hWnd = hWnd;			// Save pointer to window object in Win32 window class dataspace		::SetWindowLong(hWnd, GWL_USERDATA, reinterpret_cast<LONG>(topWindow));	}	else			// Assume the window object pointer is in class dataspace		topWindow = reinterpret_cast<oglTopWindow *>(::GetWindowLong(hWnd, GWL_USERDATA));		// If pointer is not null, assume it is valid and let window object process msg	if (topWindow != NULL)		return topWindow->ProcessWindowMsg(uMsg, wParam, lParam);	return DefWindowProc(hWnd, uMsg, wParam, lParam);}

When I create the window class, I do:

	memset(&windowClass, 0, sizeof(windowClass));	windowClass.style		= CS_OWNDC;		// If double clicks are needed, add in the style	if (handleDoubleClick)		windowClass.style		|= CS_DBLCLKS;	windowClass.cbClsExtra	= 0;		// Each window instance will have pointer to the C++ object	windowClass.cbWndExtra	= sizeof(this);	windowClass.hbrBackground = (HBRUSH)GetStockObject( BLACK_BRUSH );	windowClass.hCursor     = WindowsCursor();	windowClass.hIcon       = WindowsIcon();	windowClass.hInstance   = hInst;	windowClass.lpfnWndProc = (WNDPROC)WndProc;	windowClass.lpszClassName = winClassName;		// Let subclass have a chance at it	OnCreateWindowClass(windowClass);

I make room in the cbWndExtra area that allows me a place to put the ''this'' pointer of the class to receive the windows messages.

When I create the window, I pass ''this'':

::CreateWindow(windowClassName.c_str(), windowTitle.c_str(), winStyle,		0, 0, adjustedWinRect.right - adjustedWinRect.left, adjustedWinRect.bottom - adjustedWinRect.top,		NULL, NULL, hInst, this);

Then in my class, I have the function that handles the windows messages:

LRESULT oglTopWindow::ProcessWindowMsg(UINT uMsg, WPARAM wParam, LPARAM lParam)

Let me know if you have any questions.


- onebeer

It''s nearly working I quess... there is no error anymore, but I can''t draw anything in a window could you give some link to the one of the article you have mentioned about ( if u have one )??
anyway greeeaaat thanx

Try this article.

Enigma

quote:

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Original post by Enigma
Try this article.

Enigma

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Thanx a looot - this is exactly what i needed.