Thread: Having Trouble with CreateWindowEx

Code:

	s = WS_POPUP;
	xs = WS_EX_APPWINDOW;
	if(!(hwn = CreateWindowEx(xs,"OpenGL",WINDOW_NAME,s,0,0,rect.right-rect.left,rect.bottom-rect.top,NULL,NULL,hin,NULL))) {
		error[8] = true;
		exerror[8] = GetLastError();
	}

Given the above, the CreateWindowEx function is returning NULL, so hwn is set to null, MSDN says that I should use GetLastError to find extended information, but GetLastError is returning 0...

I have triple checked all the parameters, they seem to be fine.

Yes, I even considered that OpenGL may have been registered by something eles, so I changed it to a more unique string. Still no luck.

Its still not working, but im making progress.

I dont think the instance is right. Let me post my code up to the part that this is not working.

Code:

	

bool cWindowManager::CreateWin(int p_w, int p_h, int p_b) {
	
	//=============================================================================
	//	Signal function callbacks, sends these signals to the sigproc function
	//=============================================================================

	signal(SIGSEGV, SignalProc);
	signal(SIGTERM, SignalProc);
	signal(SIGILL, SignalProc);

	//=============================================================================
	//	Default init window variables
	//=============================================================================

	hdc=NULL;
	hwn=NULL;
	hrc=NULL;

	//=============================================================================
	//	assign the width and height to variables
	//=============================================================================
	
	width = p_w;
	height = p_h;
	bits = p_b;

	//=============================================================================
	//	Set the windows desired size
	//=============================================================================

	rect.left = 0;
	rect.right = width;
	rect.top = 0;
	rect.bottom = height;

	//=============================================================================
	//	Grab an instance for the window
	//=============================================================================
	
	if(!(hin = GetModuleHandle(NULL))) {
		error[0] = true;
		exerror[0] = GetLastError();
	}
	//=============================================================================
	//	Setup the window style
	//=============================================================================

	wc.cbClsExtra =		0;
	wc.cbWndExtra =		0;
	wc.hbrBackground =	NULL;
	wc.hCursor =		NULL;
	wc.hIcon =			NULL;
	wc.hInstance =		hin;
	wc.lpfnWndProc =	(WNDPROC) WindowProc;
	wc.lpszClassName =	"EndAgeOpenGLWindow";
	wc.lpszMenuName =	NULL;
	wc.style =			CS_HREDRAW | CS_VREDRAW | CS_OWNDC;

	//=============================================================================
	//	Register the window class
	//=============================================================================

	if(!RegisterClass(&wc)) error[1] = true;

	//=============================================================================
	//	Setup device mode
	//=============================================================================

	ss.dmSize =			sizeof(ss);
	ss.dmPelsHeight =	height;
	ss.dmPelsWidth =	width;
	ss.dmBitsPerPel =	bits;
	ss.dmFields =		DM_BITSPERPEL | DM_PELSWIDTH | DM_PELSHEIGHT;

	//=============================================================================
	//	go into fullscreen mode
	//=============================================================================

	int errorcode = ChangeDisplaySettings(&ss,CDS_FULLSCREEN);
	switch(errorcode) {
		case DISP_CHANGE_RESTART:
			error[2] = true;
			break;
		case DISP_CHANGE_BADFLAGS:
			error[3] = true;
			break;
		case DISP_CHANGE_BADPARAM:
			error[4] = true;
			break;
		case DISP_CHANGE_FAILED:
			error[5] = true;
			break;
		case DISP_CHANGE_BADMODE:
			error[6] = true;
			break;
		case DISP_CHANGE_NOTUPDATED:
			error[7] = true;
			break;	
	}
	
	//=============================================================================
	//	setup window styles
	//=============================================================================
	
	s = WS_OVERLAPPEDWINDOW;
	xs = WS_EX_APPWINDOW;

	//=============================================================================
	//	Adjust the window rect
	//=============================================================================

	AdjustWindowRectEx(&rect,s,false,xs);

	//=============================================================================
	//	Create the window
	//=============================================================================

	if(!(hwn = CreateWindowEx(xs,"EndAgeOpenGLWindow",WINDOW_NAME,s,0,0,rect.right-rect.left,rect.bottom-rect.top,NULL,NULL,hin,NULL))) {
		error[8] = true;
		exerror[8] = GetLastError();
	}

Now, everytime I run the debugger hin starts with some junk value, after that segment it is set to 0x00400000. If I expand the hin variable one level in the watch window it says unused and has a bunch of numbers. Let me post a screenshot of the watch window.

http://img64.photobucket.com/albums/...n/codeprob.png

Its not returning NULL, so its not an error, I dont know what it is but I think it is the reason that CreateWindowEx dosent work.

The only other thing I can think of is that the WindowProc function is in anoter source file and this file has an extern to it, but I dont see how that could matter.


My system is a Laptop. Toshiba Satellite P25
2.8 Ghz P4 HT
800Mhz FSB
512 Mb DDR RAM
Geforce FX Go 32 Mb

The system has a 17' widescreen display and it runs at 1440 x 900 resolution. This code is just a copy and paste from an old program and that program works fine with the code and the resolution, but I figured it was worth mentioning.

I remain 'at a loss'...

I ran a DXDIAG, nothing was flagged.

So where is hin declared anyway?

A member of the class cWindowManager

Code:

class cWindowManager {
public:
	cWindowManager();
	bool CreateWin(int width, int height, int bits);
	bool DestroyWin();
	void SwapFrameBuffer();

	int GetHeight() { return height; };
	int GetWidth() { return width; };
	int GetBits() { return bits; };

private:
	void	WriteError(short code);

	ofstream	outfile;
	int			width;
	int			height;
	int			bits;	
	bool		error[MAX_WINDOW_ERRORS];
	DWORD		exerror[MAX_WINDOW_ERRORS];
	HDC			hdc;	//Device Context
	HGLRC		hrc;	//Render Context
	HWND		hwn;	//Window Handle
	HINSTANCE	hin;	//Instance
	RECT		rect;	//Screen Rectangle
	WNDCLASS	wc;		//Window Class
	DEVMODE		ss;		//Screen Settings
	DWORD		s;		//Style
	DWORD		xs;		//Extended Style
	short		depth;	//Depthbuffer Specification
	unsigned int pf;	//Pixel Format
};

ok, the window proc is the problem, I put the DefWindowProc as the only one and the window was created.

AHH, I finally got it.

Code:

LRESULT CALLBACK WindowProc(HWND p_hwn,UINT p_msg,WPARAM p_wparam,LPARAM p_lparam) {
	GameClient->ProcessIO(p_hwn, p_msg, p_wparam, p_lparam);
	return 0;
}

I just removed the return 0; and added a return statement before the ProcessIO call.

Thanks for the help guys, im so glad that I finally got that fixed. Man, I looked at that code so many times and it never hit me that that was wrong.. whoops.