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Window->Not Work?

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Started by Spintwo October 09, 2003 07:09 PM

8 comments, last by Spintwo 20 years, 6 months ago

Spintwo

358

Author

October 09, 2003 07:09 PM

Why doesn''t this work?


#include "declare.h"
#include <windows.h>
///////////////////////////////////

LRESULT CALLBACK WindowProc(HWND hwnd,
							UINT msg,
							WPARAM wparam,
							LPARAM lparam)
{
	PAINTSTRUCT ps;
	HDC hdc;
	
	switch(msg)
	{
	case WM_CREATE:
		{
			return(0);
		}break;
	case WM_PAINT:
		{
			hdc = BeginPaint(hwnd,&ps);
			EndPaint(hwnd,&ps);
			return(0);
		}break;
	case WM_DESTROY:
		{
			PostQuitMessage(0);
			return(0);
		}break;
	default:break;
	}

	return (DefWindowProc(hwnd, msg, wparam, lparam));

}


int	WINAPI WinMain(HINSTANCE hinstance, HINSTANCE hprevinstance,
				   LPSTR lpcmdline, int nshowcmd)
{


	WNDCLASSEX	winclass = 
	{
		winclass.cbSize = sizeof(WNDCLASSEX),
		CS_DBLCLKS | CS_OWNDC | CS_HREDRAW | CS_VREDRAW,
		WindowProc,
		0,
		0,
		hinstance,
		LoadIcon(NULL, IDI_APPLICATION),
		LoadCursor(NULL, IDC_ARROW),
		GetStockObject(BLACK_BRUSH),
		NULL,
		"WINCLASS1",
		LoadIcon(NULL, IDI_APPLICATION)
	};

	if (!RegisterClassEx(&winclass))
		return(0);

	if (!(hwnd = CreateWindowEx(NULL,
			"WINCLASS1",
			"cPong",
			WS_POPUP | WS_VISIBLE,
			0,0,
			SCREENWIDTH,
			SCREENHEIGHT,
			NULL,
			NULL,
			hinstance,
			NULL)))
		return(0);

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

	return(msg.wparam);

}

(declare.h)


#ifndef _DECLARE_VARIABLES_
#define _DECLARE_VARIABLES_
////////////////////////////////////////

#define	WIN32_LEAN_AND_MEAN
#define SCREENWIDTH 640
#define SCREENHEIGHT 480
////////////////////////////////////////

#endif

UberGeek

138

October 09, 2003 09:13 PM

I cannot stress how that is a BAD way to ask a question - not only do I not know what the problem is, but I don''t even know if it''s compile time, run time, being caused by something else on your computer, etc. Next time tell us!

Anyways:

default:break; }
return (DefWindowProc(hwnd, msg, wparam, lparam));

These two lines are wrong. You want to do the call to DefWindowProc for the default: case, and you generally return zero yourself. So change them too:

default:
return (DefWindowProc(hwnd, msg, wparam, lparam));
}
return 0;

FtMonkey

122

October 09, 2003 09:25 PM

Does that even compile? Well after you do what UberGeek said take a look at this also:

#include <windows.h>///////////////////////////////////LRESULT CALLBACK WindowProc(HWND hwnd,							UINT msg,							WPARAM wparam,							LPARAM lparam){	PAINTSTRUCT ps;	HDC hdc;		switch(msg)	{	case WM_CREATE:		{			return(0);		}break;	case WM_PAINT:		{			hdc = BeginPaint(hwnd,&ps);			EndPaint(hwnd,&ps);			return(0);		}break;	case WM_DESTROY:		{			PostQuitMessage(0);			return(0);		}break;	default:          return DefWindowProc(hwnd,msg,wparam,lparam);	}     return 0;}int	WINAPI WinMain(HINSTANCE hinstance, HINSTANCE hprevinstance,				   LPSTR lpcmdline, int nshowcmd){	HWND hwnd; //<--not declared	MSG msg;//<- same	WNDCLASSEX	winclass = 	{		winclass.cbSize = sizeof(WNDCLASSEX),		CS_DBLCLKS | CS_OWNDC | CS_HREDRAW | CS_VREDRAW,		WindowProc,		0,		0,		hinstance,		LoadIcon(NULL, IDI_APPLICATION),		LoadCursor(NULL, IDC_ARROW),		(HBRUSH)GetStockObject(BLACK_BRUSH),//<- U need to cast this		NULL,		"WINCLASS1",		LoadIcon(NULL, IDI_APPLICATION)	};	if (!RegisterClassEx(&winclass))		return(0);	if (!(hwnd = CreateWindowEx(NULL,			"WINCLASS1",			"cPong",			WS_POPUP | WS_VISIBLE,			0,0,			SCREENWIDTH,			SCREENHEIGHT,			NULL,			NULL,			hinstance,			NULL)))		return(0);	while(GetMessage(&msg,NULL,0,0))	{		TranslateMessage(&msg);		DispatchMessage(&msg);	}	return(msg.wParam); //<- spelling error}

EDIT: BTW some info on what the problem is would really make things easier...

[edited by - FtMonkey on October 9, 2003 10:28:23 PM]

The monkeys are listening...

Spintwo

358

Author

October 09, 2003 10:13 PM

Thanks. It''s working now. My question is, why is msg.wParam not msg.wparam because in my CALLBACK, I declared WPARAM as wparam...

FtMonkey

122

October 09, 2003 10:17 PM

That''s not related to your callback MSG is a separate struct which is defined like this...

typedef struct tagMSG { // msg
HWND hwnd;
UINT message;
WPARAM wParam;
LPARAM lParam;
DWORD time;
POINT pt;
} MSG;

The monkeys are listening...

Spintwo

358

Author

October 09, 2003 10:30 PM

ok. Now, I changed my main message handling loop to a PeekMessage and it compiles ok but I get the following Linker error:

cannot open Debug/cPong.exe for writing
Error executing link.exe.

WTH??!!
(source included below)

#include "declare.h"#include <windows.h>///////////////////////////////////LRESULT CALLBACK WindowProc(HWND hwnd,							UINT msg,							WPARAM wparam,							LPARAM lparam){	PAINTSTRUCT ps;	HDC hdc;		switch(msg)	{	case WM_CREATE:		{			return(0);		}break;	case WM_PAINT:		{			hdc = BeginPaint(hwnd,&ps);			EndPaint(hwnd,&ps);			return(0);		}break;	case WM_DESTROY:		{			PostQuitMessage(0);			return(0);		}break;	default:		{		return (DefWindowProc(hwnd, msg, wparam, lparam));		}	}}int	WINAPI WinMain(HINSTANCE hinstance, HINSTANCE hprevinstance,				   LPSTR lpcmdline, int nshowcmd){	HWND hwnd;	MSG msg;	WNDCLASSEX	winclass = 	{		winclass.cbSize = sizeof(WNDCLASSEX),		CS_DBLCLKS | CS_OWNDC | CS_HREDRAW | CS_VREDRAW,		WindowProc,		0,		0,		hinstance,		LoadIcon(NULL, IDI_APPLICATION),		LoadCursor(NULL, IDC_ARROW),		(HBRUSH)GetStockObject(BLACK_BRUSH),		NULL,		"WINCLASS1",		LoadIcon(NULL, IDI_APPLICATION)	};	if (!RegisterClassEx(&winclass))		return(0);	if (!(hwnd = CreateWindowEx(NULL,			"WINCLASS1",			"cPong",			WS_OVERLAPPEDWINDOW | WS_VISIBLE,			0,0,			SCREENWIDTH,			SCREENHEIGHT,			NULL,			NULL,			hinstance,			NULL)))		return(0);	while(TRUE)	{		if(PeekMessage(&msg,NULL,0,0,PM_REMOVE))		{			if(msg.message == WM_QUIT)			{				break;			}		TranslateMessage(&msg);		DispatchMessage(&msg);		}	}	return(msg.wParam);		}

lemurion

336

October 09, 2003 10:31 PM

WNDCLASSEX	winclass = 	{        winclass.cbSize = sizeof(WNDCLASSEX),		CS_DBLCLKS | CS_OWNDC | CS_HREDRAW | CS_VREDRAW,

shouldn''t this be

WNDCLASSEX winclass = {        sizeof(WNDCLASSEX),        CS_DBLCLKS | CS_OWNDC | CS_HREDRAW | CS_VREDRAW,

Matt

FtMonkey

122

October 09, 2003 10:40 PM

Make sure your program isn't still running on the desktop if it isn't is probably still on memory so press CTRL-ALT-DELETE press the processes tab and look if your program isn't still running if it is end it and it should compile...You probably didn't quit the program as you should have and it stayed resident (undead) or there is a bug in your code (it doesn't look like it though).

[edited by - FtMonkey on October 9, 2003 11:45:20 PM]

The monkeys are listening...

Spintwo

358

Author

October 09, 2003 10:58 PM

Thanks monkey. I would have thought of that, actually I did, and when I deleted it from the applications I thought it was gone. Didn''t think to check the processes though! And Lemurion, it works either way, I just did it to clear up ambiguities.

FtMonkey

122

October 10, 2003 12:01 AM

You are welcome, yea that's something your going to run into a lot even though you quit the program it stays in the processes most of the time because you forgot to free something from memory or something like that, so just quitting the program won't do much for you in this case since it stays resident in memory

[edited by - FtMonkey on October 10, 2003 1:04:39 AM]

The monkeys are listening...

Window->Not Work?

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