C / C++ / MFC

3-Jun-07 1:26

I am writting a button control from scratch in pure C + Win32. I have a structure as under

<br />
typedef struct tagBUTTONINFO<br />
{<br />
   TCHAR * szText;<br />
   int iLenght;<br />
   COLORREF backColor<br />
   // Other memebers...<br />
} BUTTONINFO, * PBUTTONINFO;<br />

Now on each WM_NCCREATE, I use malloc() to allocate a BUTTONINFO and set its address in USERDATA of the HWND of the window. In each WM_SETTEXT, I allocate space for the text and set in the PBUTTONINFO->szText. On WM_NCDESTROY, I deallocate the space for BUTTONINFO and the BUTTONINFO::szText as well. But in debug sessions, I get Heap Corruption Error Message. Whats wrong?

However, if you use new and delete keywords for the same tasks, no such problem occurs... whats wrong and where?

Polite Programmer

More Object Oriented then C#

Gary R. Wheeler3-Jun-07 1:44

Gary R. Wheeler

3-Jun-07 1:44

The biggest difference is that new calls the constructor for the object being allocated, while malloc() only allocates memory. Even though you may not define one, a simple struct has a default constructor provided by the compiler. I believe the default constructor under debug initializes the allocated memory to zero. This is probably setting your structure to a 'good' initial state (pointers get initialized to NULL). With malloc(), that initialization isn't happening.

Software Zen: delete this;

Fold With Us![^]

Polite Programmer3-Jun-07 1:47

3-Jun-07 1:47

But the constructor is not needed to dot that because after executing the malloc(), I immediatly call ZeroMemory like this.

PBUTTONINFO pButtonInfo = (PBUTTONINFO) malloc (sizeof (BUTTONINFO));<br />
ZeroMemory ((LPVOID) pButtonInfo, sizeof (BUTTONINFO));

Polite Programmer

More Object Oriented then C#

Polite Programmer3-Jun-07 1:57

3-Jun-07 1:57

One more thing, The GlobalAlloc() and GlobalFree() also act the similar way as the malloc() does.

Polite Programmer

More Object Oriented then C#

Gary R. Wheeler3-Jun-07 1:59

Gary R. Wheeler

3-Jun-07 1:59

Hmm. Myself, I always prefer the new/delete approach over malloc()/free(), because these sorts of issues don't tend to arise as often.

There isn't a significant difference between the performance of the two approaches. Is there any particular reason you're using malloc()?

Software Zen: delete this;

Fold With Us![^]

CPallini3-Jun-07 3:47

CPallini

3-Jun-07 3:47

Because he wants to use pure C.

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

Matthew Faithfull3-Jun-07 3:08

Matthew Faithfull

3-Jun-07 3:08

You'll get those heap corruption messages in Debug only because in debug the CRT ( C RunTime library ) is checking up on you and picking up the mismatch between malloc and delete. The Debug CRT new adds extra info to the allocation to indicate what sort of allocation it is, i.e. you did it or it's internal to the CRT or thread specific or whatever. When you do the delete, it checks this info to make sure it matches but because you called malloc the extra info didn't get initialised and it's either wrong or missing. In Release the extra info and checking is cut for performance so you don't get the errors.

Conclusion: For a happy life you really do need to match malloc with free and new with delete Wink | ;)

Nothing is exactly what it seems but everything with seems can be unpicked.

CPallini3-Jun-07 3:48

CPallini

3-Jun-07 3:48

Try to post the relevant code.
Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

Stephen Hewitt3-Jun-07 14:08

Stephen Hewitt

3-Jun-07 14:08

I give the following advice about once a month (more recently); it often helps me track down the nastier heap errors:

Try enabling the page heap[^] for your process. Follow these steps:
1. Download and install WinDBG[^].
2. Select “Start”->“All Programs”->“Debugging Tools for Windows”->“Global Flags”.
3. Select the “Image File” tab.
4. In the “Image: (TAB to refresh)” edit control enter the name of your app then press TAB. Just the name with the extension; not the full path.
5. Tick the following:
- “Enable page heap”
- “Enable heap tail checking”
- “Enable heap free checking”
- “Enable heap parameter checking”
- “Enable heap validation on call”
- “Create user mode stack trace database”
6. Press “Apply”.
7. Debug your application. Any debugger will do but with WinDBG you have access to the stack traces of allocations via the !heap –p –a command, for example. When a heap problem is detected a breakpoint will be generated.
8. When done un-tick all the options you ticked, press “Apply” then dismiss GFlags. This step is important as if it’s skipped all applications named as entered in step 4 will run with the page heap enabled.

Note that when using the page heap your application will run much slower than normal and consume way more memory. It’s good to have a beefy machine to do such tests; and such tests should be ran regularly on all applications you develop as part of regular testing activities. If I find a part of my application that’s too slow with the page heap enabled I optimize the memory allocation in that region.

Steve

Polite Programmer3-Jun-07 20:00

3-Jun-07 20:00

Reason for using malloc() stuff is that I want to be pure in C.

What I am doing?

1.... I want to write a pure C control to teach myself internals of Win32 Message Architecture.
2... When done with this, I will burry that control (a simple button control yet...) into a DLL.
3... When done with the DLL, I will try to write a COM wrapper around it that too in pure C to check whether it can be used with VB, and .NET.

Friends one more thing... my every malloc() is having a free() but still facing problem. And one of our felllows is very much right, the problem only occurs in Debug sessions.

Here is the source code.

Please consider the following functions specially.... Are they correct?

a) AllocateButtonInfoFor()
b) DeleteButtonInfo()
c) OnNCCreate()
d) OnSetText()

First is the ButtonControl.h
============================

#ifndef __BUTTON_CONTROL_H__<br />
#define __BUTTON_CONTROL_H__<br />
#include "stdafx.h"<br />
<br />
#define BUTTON_CONTROL_CLASS			TEXT("BUTTON_CONTROL_safsf")<br />
<br />
<br />
#ifdef __INCLUDE_BUTTONCONTROL_PRIVATES__<br />
<br />
/* Depicts the state of the button */<br />
typedef enum tagBUTTONSTATE<br />
{<br />
	NORMAL = 2,<br />
	HOVER,<br />
	PRESSED,<br />
	DISABLED<br />
<br />
} BUTTONSTATE;<br />
<br />
/* Structure to hold the information of the button*/<br />
typedef struct tagBUTTONINFO<br />
{<br />
//	HWND hWnd;							/* Handle of the button itself */<br />
	TCHAR * szText;						/* The caption of button */<br />
	int nTextLength;					/* Length of caption */<br />
	HPEN borderColor;					/* The outline color */<br />
	COLORREF textColor;					/* The Text Color of the button */<br />
	HBRUSH backColor;					/* The background color of the button */<br />
	HFONT font;							/* The font of the text */<br />
	HPEN borderColorPressed;			/* The border color in pressed form*/<br />
	COLORREF textColorPressed;			/* The text color in pressed form */<br />
	HBRUSH backColorPressed;			/* The back color in pressed form */<br />
	HFONT fontPressed;					/* The font in pressed form */<br />
	HPEN borderColorHover;				/* The border color in hover form*/<br />
	COLORREF textColorHover;			/* The text color in hover form */<br />
	HBRUSH backColorHover;				/* The back color in hover form */<br />
	HFONT fontHover;					/* The font in hover form */<br />
<br />
	BUTTONSTATE state;					/* The state of the button */<br />
<br />
} BUTTONINFO, * PBUTTONINFO;<br />
<br />
/* ButtonInfo Allocation */<br />
//HANDLE	CreateHeapIfNeeded();<br />
//BOOL	DestroyHeapIfNeeded(HANDLE);<br />
<br />
PBUTTONINFO AllocateButtonInfoFor(HWND hWnd);<br />
PBUTTONINFO PickButtonInfo(HWND hWnd);<br />
BOOL DropButtonInfo(HWND hWnd);<br />
void DeleteButtonInfo(HWND hWnd);<br />
void SetButtonDefaults(HWND hWnd, PBUTTONINFO pButtonInfo);<br />
<br />
void DrawButton(HWND hWnd, PBUTTONINFO pButtonInfo, HDC hdc);<br />
<br />
/* The window procedure. */<br />
LRESULT CALLBACK ButtonProc(HWND, UINT, WPARAM, LPARAM);<br />
<br />
/* The Button Event Handlers */<br />
<br />
<br />
BOOL	OnNCCreate(HWND hwnd, LPCREATESTRUCT lpCreateStruct);<br />
void	OnNCDestroy(HWND);<br />
void	OnPaint(HWND);<br />
void	OnInitButton(HWND hWnd);<br />
void	OnMouseButtonDown(HWND hWnd, int x, int y);<br />
void	OnMouseButtonUp(HWND hWnd, int x, int y);<br />
INT		OnGetText(HWND, int, LPTSTR);<br />
INT		OnGetTextLength(HWND);<br />
BOOL	OnSetText(HWND hWnd, LPCTSTR);<br />
<br />
//void	OnDestroy(HWND);<br />
/*<br />
BOOL	OnCreate(HWND, LPCREATESTRUCT);<br />
<br />
<br />
void	OnEnable(HWND, BOOL);<br />
<br />
<br />
<br />
HFONT	OnGetFont(HWND);<br />
<br />
void	OnSetFont(HWND hWnd, HFONT hFont, BOOL fRedraw);<br />
void	OnMouseButtonDown(HWND, int nMask, int x, int y);<br />
void	OnMouseButtonUp(HWND, int nMask, int x, int y);<br />
*/<br />
#endif /* __INCLUDE_BUTTONCONTROL_PRIVATES__ */<br />
<br />
// The Button Messages used to set and get properties.<br />
<br />
#define BCM_SETBORDERPEN				WM_USER + 10	/* WPARAM	= HPEN			*/<br />
#define BCM_GETBORDERPEN				WM_USER + 11	/* Return	= HPEN			*/<br />
#define BCM_SETCAPTIONCOLOR				WM_USER + 12	/* WPARAM	= COLORREF		*/<br />
#define BCM_GETCAPTIONCOLOR				WM_USER + 13	/* Return	= COLORREF		*/<br />
#define BCM_SETBACKGNDBRUSH				WM_USER + 14	/* WPARAM	= HBRUSH		*/<br />
#define BCM_GETBACKGNDBRUSH				WM_USER + 15	/* Return	= HBRUSH		*/<br />
#define BCM_SETBUTTONSTATE				WM_USER + 16	/* WPARAM	= BUTTONSTATE	*/<br />
#define BCM_GETBUTTONSTATE				WM_USER + 17	/* Return	= BUTTONSTATE	*/<br />
#define BCM_INITBUTTON					WM_USER + 18	/* NULL */<br />
<br />
// Initializes the button control<br />
HRESULT InitButtonControl(HINSTANCE hInstance);<br />
#endif /*__BUTTON_CONTROL_H__*/

Second is ButtonControl.cpp
===========================

#include "stdafx.h"<br />
#define __INCLUDE_BUTTONCONTROL_PRIVATES__		/* So that we may have private functions. */<br />
#include "ButtonControl.h"<br />
<br />
//static ULONG gButtonCount = 0;<br />
//static HANDLE ghHeap = NULL;<br />
<br />
/***********************************************************************\<br />
FUNCTION:			InitButtonControl<br />
PURPOSE:			Registers the button class<br />
ARGS:				HINSTANCE hInstance<br />
RETURN:				The result of the registration<br />
\***********************************************************************/<br />
HRESULT InitButtonControl(HINSTANCE hInstance)<br />
{<br />
	WNDCLASSEX wc;<br />
<br />
	wc.cbClsExtra			= 0;<br />
	wc.cbSize				= sizeof(WNDCLASSEX);<br />
	wc.cbWndExtra			= 0;<br />
	wc.hbrBackground		= (HBRUSH)(COLOR_WINDOW + 1);<br />
	wc.hCursor				= LoadCursor(NULL, IDC_ARROW);<br />
	wc.hIcon				= LoadIcon(NULL, IDI_APPLICATION);<br />
	wc.hIconSm				= LoadIcon(NULL, IDI_APPLICATION);<br />
	wc.hInstance			= hInstance;<br />
	wc.lpfnWndProc			= ButtonProc;<br />
	wc.lpszClassName		= BUTTON_CONTROL_CLASS;<br />
	wc.lpszMenuName			= NULL;<br />
	wc.style				= CS_HREDRAW | CS_VREDRAW |<br />
								CS_GLOBALCLASS;<br />
	<br />
	//HeapCreate(HC<br />
	<br />
	//DWORD dwErr = GetLastError();<br />
	return RegisterClassEx(&wc);<br />
}<br />
<br />
<br />
<br />
/***********************************************************************\<br />
FUNCTION:			AllocateButtonInfoFor<br />
PURPOSE:			Allocate and attaches the BUTTONINFO structure<br />
ARGS:				Handle to the button<br />
RETURN:				Pointer to allocated BUTTONINFO structure<br />
\***********************************************************************/<br />
PBUTTONINFO AllocateButtonInfoFor(HWND hWnd)<br />
{<br />
	if(!hWnd)<br />
		return NULL;<br />
<br />
	//PBUTTONINFO hMem = (PBUTTONINFO) GlobalAlloc(GMEM_FIXED, sizeof(BUTTONINFO));<br />
	PBUTTONINFO hMem = (PBUTTONINFO) malloc(sizeof(BUTTONINFO));<br />
	//PBUTTONINFO hMem = new BUTTONINFO();<br />
<br />
	if(!hMem)<br />
		return NULL;<br />
<br />
	SetWindowLong(hWnd, GWL_USERDATA, (LONG)hMem);<br />
<br />
	SetButtonDefaults(hWnd, hMem);<br />
<br />
	return hMem;<br />
<br />
<br />
}<br />
<br />
<br />
/***********************************************************************\<br />
FUNCTION:			PickButtonInfo<br />
PURPOSE:			Extracts the BUTTONINFO structure from the button<br />
ARGS:				Handle to the button<br />
RETURN:				Pointer to the extracted BUTTONINFO Structure<br />
\***********************************************************************/<br />
PBUTTONINFO PickButtonInfo(HWND hWnd)<br />
{<br />
	if(!hWnd)<br />
		return NULL;<br />
<br />
	PBUTTONINFO hMem = (PBUTTONINFO) GetWindowLong(hWnd, GWL_USERDATA);<br />
<br />
	if(!hMem)<br />
		return NULL;<br />
<br />
	//PBUTTONINFO pButtonInfo = (PBUTTONINFO) GlobalLock(hMem);<br />
<br />
	DWORD dw = GetLastError();<br />
<br />
	return hMem;<br />
<br />
<br />
}<br />
<br />
/***********************************************************************\<br />
FUNCTION:			DropButtonInfo<br />
PURPOSE:			Locks the BUTTONINFO structure of the given control<br />
ARGS:				Handle to the control<br />
RETURN:				Succuss status of the operation<br />
\***********************************************************************/<br />
BOOL DropButtonInfo(HWND hWnd)<br />
{<br />
	if(!hWnd)<br />
		return FALSE;<br />
<br />
	PBUTTONINFO hMem = (PBUTTONINFO)GetWindowLong(hWnd, GWL_USERDATA);<br />
<br />
	if(!hMem)<br />
		return FALSE;<br />
<br />
	return TRUE;<br />
<br />
<br />
}<br />
<br />
/***********************************************************************\<br />
FUNCTION:			DeleteButtonInfo<br />
PURPOSE:			Deletes the BUTTONINFO structure<br />
ARGS:				Handle to the button structure<br />
RETURN:				None<br />
\***********************************************************************/<br />
void DeleteButtonInfo(HWND hWnd)<br />
{<br />
	if(!hWnd)<br />
		return;<br />
<br />
	PBUTTONINFO pButtonInfo = PickButtonInfo(hWnd);<br />
	<br />
	if(!pButtonInfo)<br />
		return;<br />
<br />
	DeleteObject((HGDIOBJ)pButtonInfo->backColor);<br />
	DeleteObject((HGDIOBJ)pButtonInfo->borderColor);<br />
	DeleteObject((HGDIOBJ)pButtonInfo->font);<br />
	//GlobalFree((HGLOBAL)pButtonInfo->szText);<br />
	//_free_dbg((void *) pButtonInfo->szText, _NORMAL_BLOCK);<br />
	//delete [] pButtonInfo->szText;<br />
<br />
	if(pButtonInfo->szText != NULL)<br />
		free((void *)pButtonInfo->szText);<br />
	<br />
<br />
	DeleteObject((HGDIOBJ)pButtonInfo->backColorPressed);<br />
	DeleteObject((HGDIOBJ)pButtonInfo->borderColorPressed);<br />
	DeleteObject((HGDIOBJ)pButtonInfo->fontPressed);<br />
<br />
<br />
	//GlobalFree((HGLOBAL)GetWindowLong(hWnd, GWL_USERDATA));<br />
	void * hMem = (void *) GetWindowLong(hWnd, GWL_USERDATA);<br />
<br />
	if(hMem != NULL)<br />
		free((void *)GetWindowLong(hWnd, GWL_USERDATA));<br />
	//delete (PBUTTONINFO)GetWindowLong(hWnd, GWL_USERDATA);<br />
}<br />
<br />
/***********************************************************************\<br />
FUNCTION:			SetButtonDefaults<br />
PURPOSE:			Sets the default values for the button<br />
ARGS:				Handle to button<br />
RETURN:				None<br />
\***********************************************************************/<br />
void SetButtonDefaults(HWND hWnd, PBUTTONINFO pButtonInfo)<br />
{<br />
	//PBUTTONINFO pButtonInfo = PickButtonInfo(hWnd);<br />
<br />
	if(!pButtonInfo)<br />
		return;<br />
<br />
	//HWND hWnd = pButtonInfo->hWnd;<br />
<br />
	ZeroMemory((PVOID)pButtonInfo, sizeof(BUTTONINFO));<br />
<br />
	pButtonInfo->backColor		= (HBRUSH) CreateSolidBrush(RGB(123,123,123));<br />
	pButtonInfo->borderColor	= (HPEN) CreatePen(PS_SOLID, 1, RGB(200,10,19));<br />
	pButtonInfo->font			= (HFONT) GetStockFont(ANSI_VAR_FONT);<br />
	pButtonInfo->textColor		= RGB(255, 255, 255);<br />
	pButtonInfo->state			= NORMAL;<br />
	pButtonInfo->szText			= NULL;<br />
	//lstrcpy(pButtonInfo->szText, TEXT("Flat Button"));<br />
	pButtonInfo->nTextLength	= 0;<br />
<br />
	pButtonInfo->backColorPressed	= CreateSolidBrush(RGB(200,180,150));<br />
	pButtonInfo->borderColorPressed	= (HPEN) GetStockObject(BLACK_PEN);<br />
	pButtonInfo->fontPressed		= (HFONT)GetStockObject(ANSI_VAR_FONT);<br />
	pButtonInfo->textColorPressed	= RGB(0,0,0);<br />
	<br />
<br />
	/* Set the background color */<br />
//	pButtonInfo->hWnd;<br />
	//SetClassLong(hWnd, GCL_HBRBACKGROUND, (LONG)pButtonInfo->backColor);<br />
<br />
	//DropButtonInfo(hWnd);<br />
}<br />
<br />
/***********************************************************************\<br />
FUNCTION:			DrawButton<br />
PURPOSE:			Draws the button according to the button status<br />
ARGS:				HWND: Handle to the button<br />
					HDC Device Context. If NULL, obtained automatically.<br />
					But in case of WM_PAINT, it should not be null.<br />
RETURN:				None<br />
\***********************************************************************/<br />
void DrawButton(HWND hWnd, PBUTTONINFO pButtonInfo, HDC hdc)<br />
{<br />
	static TCHAR szBuffer[256];<br />
<br />
	if(!pButtonInfo)<br />
		return;<br />
<br />
	//HWND hWnd = pButtonInfo->hWnd;<br />
<br />
	if(!IsWindow(hWnd))<br />
		return;<br />
<br />
	<br />
	HDC hDC = NULL;<br />
<br />
	if(hdc == NULL)<br />
		hDC = GetDC(hWnd);<br />
	else<br />
		hDC = hdc;<br />
<br />
	// PBUTTONINFO pButtonInfo = PickButtonInfo(hWnd);<br />
<br />
	RECT rect;<br />
<br />
	GetClientRect(hWnd, &rect);<br />
	<br />
	if(pButtonInfo->state == NORMAL)<br />
	{<br />
		/* Draw Normal */<br />
			/* Draw Hover State */<br />
		<br />
		SelectObject(hDC, (HGDIOBJ)pButtonInfo->backColor);<br />
		SelectObject(hDC, (HGDIOBJ)pButtonInfo->borderColor);<br />
		SetTextColor(hDC, pButtonInfo->textColor);<br />
		SetBkMode(hDC, TRANSPARENT);<br />
<br />
		/* Fill the rectangle with the background color */<br />
		FillRect(hDC, &rect, pButtonInfo->backColor);<br />
<br />
<br />
	}<br />
<br />
	if(pButtonInfo->state == HOVER)<br />
	{<br />
	<br />
	}<br />
<br />
	if(pButtonInfo->state == PRESSED)<br />
	{<br />
		// Draw Pressed<br />
		SelectObject(hDC, (HGDIOBJ)pButtonInfo->backColorPressed);<br />
		SelectObject(hDC, (HGDIOBJ)pButtonInfo->borderColorPressed);<br />
		SetTextColor(hDC, pButtonInfo->textColorPressed);<br />
		SetBkMode(hDC, TRANSPARENT);<br />
<br />
		FillRect(hDC, &rect, pButtonInfo->backColorPressed);<br />
	}<br />
<br />
	if(pButtonInfo->state == DISABLED)<br />
	{<br />
		// Draw Disabled<br />
	}<br />
<br />
		<br />
<br />
		Rectangle(hDC, rect.left, rect.top, rect.right, rect.bottom);<br />
		<br />
		<br />
		//int i = GetWindowText(hWnd, szBuffer, 256);<br />
<br />
		<br />
		DrawText(hDC, pButtonInfo->szText,<br />
					  pButtonInfo->nTextLength,<br />
					  &rect,<br />
					  DT_SINGLELINE | DT_VCENTER | DT_CENTER);<br />
<br />
		<br />
<br />
		/*<br />
		DrawText(hDC, szBuffer,<br />
					  i,<br />
					  &rect,<br />
					  DT_SINGLELINE | DT_VCENTER | DT_CENTER);<br />
	   */<br />
<br />
<br />
<br />
	if(hdc == NULL)<br />
		ReleaseDC(hWnd, hDC);<br />
<br />
}<br />
<br />
/***********************************************************************\<br />
FUNCTION:			ButtonProc<br />
PURPOSE:			Handles the messages for the button<br />
ARGS:				Same as to WndProc<br />
<br />
HANDLES:<br />
WM_PAINT<br />
<br />
<br />
WM_ENABLE<br />
<br />
WM_CREATE<br />
WM_NCCREATE<br />
WM_NCDESTROY<br />
<br />
WM_SIZE<br />
WM_MOVE<br />
WM_MOVING<br />
WM_WINDOWPOSCHANGED<br />
WM_WINDOWPOSCHANGING<br />
<br />
WM_LBUTTONDOWN<br />
WM_LBUTTONUP<br />
<br />
WM_GETTEXT<br />
WM_SETTEXT<br />
WM_GETTEXTLENGH<br />
WM_SETFONT<br />
WM_GETFONT<br />
WM_GETMINMAXINFO<br />
<br />
BCM_SETBORDERPEN<br />
BCM_GETBORDERPEN<br />
BCM_SETCAPTIONCOLOR<br />
BCM_GETCAPTIONCOLOR<br />
BCM_SETBACKGNDBRUSH<br />
BCM_GETBACKGNDBRUSH<br />
BCM_SETBUTTONSTATE<br />
BCM_GETBUTTONSTATE<br />
<br />
\***********************************************************************/<br />
LRESULT CALLBACK ButtonProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)<br />
{<br />
	switch(msg)<br />
	{<br />
		//HANDLE_WM_NCCREATE(hWnd, wParam, lParam, OnNCCreate);<br />
	/*=======================================================<br />
			WM_NCCREATE<br />
	  ======================================================*/<br />
	case WM_NCCREATE:<br />
		{<br />
			return (LRESULT) OnNCCreate(hWnd, (LPCREATESTRUCT)lParam);<br />
		}<br />
<br />
	case WM_CREATE:<br />
		{<br />
			PostMessage(hWnd, BCM_INITBUTTON, 0, 0);<br />
			return TRUE;<br />
		}<br />
<br />
	case BCM_INITBUTTON:<br />
		{<br />
			//OnInitButton(hWnd);<br />
			return 0;<br />
		}<br />
	/*=======================================================<br />
			WM_NCDESTROY<br />
	  ======================================================*/<br />
	case WM_DESTROY:<br />
		{<br />
			OnNCDestroy(hWnd);<br />
			return 0;<br />
		}<br />
<br />
	/*=======================================================<br />
		WM_PAINT<br />
	 ======================================================*/<br />
	case WM_PAINT:<br />
		{<br />
			OnPaint(hWnd);<br />
			/*<br />
			PAINTSTRUCT ps;<br />
			HDC hdc = BeginPaint(hWnd, &ps);<br />
			RECT rect;<br />
			GetClientRect(hWnd, &rect);<br />
			Rectangle(hdc, rect.left, rect.top, rect.right, rect.bottom);<br />
			EndPaint(hWnd, &ps);<br />
			*/<br />
			return 0;<br />
		}<br />
<br />
	/*=======================================================<br />
		WM_LBUTTONDOWN<br />
	 ======================================================*/<br />
	case WM_LBUTTONDOWN:<br />
	case WM_RBUTTONDOWN:<br />
		{<br />
			OnMouseButtonDown(hWnd, LOWORD(lParam), HIWORD(lParam));<br />
			return 0;<br />
		}<br />
<br />
	/*=======================================================<br />
		WM_LBUTTONUP<br />
	 ======================================================*/<br />
	case WM_LBUTTONUP:<br />
	case WM_RBUTTONUP:<br />
		{<br />
			OnMouseButtonUp(hWnd, LOWORD(lParam), HIWORD(lParam));<br />
			return 0;<br />
		}<br />
<br />
	/*=======================================================<br />
		WM_GETTEXT<br />
	 ======================================================*/<br />
	case WM_GETTEXT:<br />
		{<br />
			return OnGetText(hWnd, (int)wParam, (LPTSTR)lParam);<br />
		}<br />
<br />
	/*=======================================================<br />
		WM_GETTEXTLENGTH<br />
	 ======================================================*/<br />
	case WM_GETTEXTLENGTH:<br />
		{<br />
			return OnGetTextLength(hWnd);<br />
		}<br />
<br />
	/*=======================================================<br />
		WM_SETTEXT<br />
	 ======================================================*/<br />
	case WM_SETTEXT:<br />
		{<br />
			return OnSetText(hWnd, (LPCTSTR)lParam);<br />
		}<br />
<br />
	<br />
/*		<br />
		HANDLE_WM_CREATE(hWnd, wParam, lParam, OnCreate);<br />
		HANDLE_WM_DESTROY(hWnd, wParam, lParam, OnDestroy);<br />
		HANDLE_WM_NCDESTROY(hWnd, wParam, lParam, OnNCDestroy);<br />
<br />
		HANDLE_WM_PAINT(hWnd, wParam, lParam, OnPaint);<br />
<br />
		HANDLE_WM_ENABLE(hWnd, wParam,lParam, OnEnable);<br />
<br />
		<br />
		HANDLE_WM_GETTEXT(hWnd, wParam, lParam, OnGetText);<br />
		HANDLE_WM_GETTEXTLENGTH(hWnd, wParam, lParam, OnGetTextLength);<br />
		HANDLE_WM_GETFONT(hWnd, wParam, lParam, OnGetFont);<br />
<br />
		HANDLE_WM_SETTEXT(hWnd, wParam, lParam, OnSetText);<br />
		HANDLE_WM_SETFONT(hWnd, wParam, lParam, OnSetFont);<br />
<br />
		//HANDLE_WM_LBUTTONDOWN(hWnd, wParam, lParam, OnMouseButtonDown);<br />
		//HANDLE_WM_LBUTTONUP(hWnd, wParam, lParam, OnMouseButtonUp);<br />
		*/<br />
<br />
	}<br />
	<br />
	return DefWindowProc(hWnd, msg, wParam, lParam);<br />
}<br />
<br />
<br />
/***********************************************************************\<br />
FUNCTION:			OnNCCreate<br />
PURPOSE:			Intializes the control for the first time<br />
ARGS:				HWND: Handle to the button<br />
					LPCREATESTRUCT pointer<br />
RETURN:				TRUE if succuss FALSE otherwise.<br />
\***********************************************************************/<br />
BOOL OnNCCreate(HWND hWnd, LPCREATESTRUCT lpCreateStruct)<br />
{<br />
	PBUTTONINFO pButtonInfo = AllocateButtonInfoFor(hWnd);<br />
	<br />
	if(!pButtonInfo)<br />
		return FALSE;<br />
<br />
	int iLen = lstrlen(lpCreateStruct->lpszName);<br />
<br />
	if(iLen > pButtonInfo->nTextLength)<br />
	{<br />
		if(pButtonInfo->szText != NULL)<br />
			free((void *)pButtonInfo->szText);<br />
		pButtonInfo->szText = (TCHAR *) malloc(iLen + 2);<br />
		//pButtonInfo->szText = new TCHAR[iLen + 1];<br />
		<br />
		if(pButtonInfo->szText == NULL)<br />
			return FALSE;<br />
	}<br />
<br />
	pButtonInfo->nTextLength = iLen;<br />
	ZeroMemory((LPVOID)pButtonInfo->szText, pButtonInfo->nTextLength);<br />
	lstrcpy(pButtonInfo->szText, lpCreateStruct->lpszName);<br />
<br />
	<br />
<br />
	return TRUE;<br />
}<br />
<br />
/***********************************************************************\<br />
FUNCTION:			OnNCDestroy<br />
PURPOSE:			De-allocates the BUTTONINFO struct<br />
ARGS:				HWND: Handle to the button<br />
RETURN:				None<br />
\***********************************************************************/<br />
<br />
void OnNCDestroy(HWND hWnd)<br />
{<br />
	DeleteButtonInfo(hWnd);<br />
}<br />
<br />
/***********************************************************************\<br />
FUNCTION:			OnPaint<br />
PURPOSE:			Paints the control<br />
ARGS:				HWND: Handle to the button<br />
RETURN:				None<br />
\***********************************************************************/<br />
<br />
void OnPaint(HWND hWnd)<br />
{<br />
	PAINTSTRUCT ps;<br />
<br />
	PBUTTONINFO pButtonInfo = PickButtonInfo(hWnd);<br />
	HDC hdc = BeginPaint(hWnd, &ps);<br />
	<br />
	//pButtonInfo->state = (BUTTONSTATE)2;<br />
	DrawButton(hWnd, pButtonInfo, hdc);<br />
	EndPaint(hWnd, &ps);<br />
<br />
	//DropButtonInfo(hWnd);<br />
	<br />
}<br />
<br />
<br />
/***********************************************************************\<br />
FUNCTION:			OnMouseButtonDown<br />
PURPOSE:			Changes the button state<br />
ARGS:				HWND: Handle to the button<br />
RETURN:				None<br />
\***********************************************************************/<br />
<br />
void OnMouseButtonDown(HWND hWnd, int x, int y)<br />
{<br />
	PBUTTONINFO pButtonInfo = PickButtonInfo(hWnd);<br />
<br />
	if(!pButtonInfo)<br />
		return;<br />
<br />
	pButtonInfo->state = PRESSED;<br />
<br />
	InvalidateRect(hWnd, NULL, TRUE);<br />
}<br />
<br />
/***********************************************************************\<br />
FUNCTION:			OnMouseButtonUp<br />
PURPOSE:			Changes the state of the button<br />
ARGS:				HWND: Handle to the button<br />
RETURN:				None<br />
\***********************************************************************/<br />
<br />
void OnMouseButtonUp(HWND hWnd, int x, int y)<br />
{<br />
	PBUTTONINFO pButtonInfo = PickButtonInfo(hWnd);<br />
<br />
	if(!pButtonInfo)<br />
		return;<br />
<br />
	pButtonInfo->state = NORMAL;<br />
	InvalidateRect(hWnd, NULL, TRUE);<br />
	<br />
	HWND hParent = GetParent(hWnd);<br />
<br />
	if(!hParent)<br />
		return;<br />
<br />
	UINT nID = GetWindowLong(hWnd, GWL_ID);<br />
<br />
	SendMessage(hParent, WM_COMMAND, MAKEWPARAM(nID, BN_CLICKED), (LONG)hWnd);<br />
}<br />
<br />
/***********************************************************************\<br />
FUNCTION:			OnGetText<br />
PURPOSE:			Gets the text of the control<br />
ARGS:				HWND: Handle to the button<br />
RETURN:				None<br />
\***********************************************************************/<br />
<br />
INT OnGetText(HWND hWnd, int nMaxLen, LPTSTR lpszBuffer)<br />
{<br />
	PBUTTONINFO pButtonInfo = PickButtonInfo(hWnd);<br />
<br />
	if(!pButtonInfo)<br />
		return -1;<br />
<br />
	<br />
	int i = 0;<br />
<br />
//	while(i < nMaxLen && i < pButtonInfo->nTextLength)<br />
//		lpszBuffer[i] = pButtonInfo->szText[i++];<br />
<br />
	lstrcpy(lpszBuffer, pButtonInfo->szText);<br />
//	lpszBuffer[i] = '\0';<br />
<br />
	return i;<br />
}<br />
<br />
/***********************************************************************\<br />
FUNCTION:			OnGetTextLength<br />
PURPOSE:			Gets the length of text of the control<br />
ARGS:				HWND: Handle to the button<br />
RETURN:				None<br />
\***********************************************************************/<br />
<br />
INT OnGetTextLength(HWND hWnd)<br />
{<br />
	PBUTTONINFO pButtonInfo = PickButtonInfo(hWnd);<br />
<br />
	if(!pButtonInfo)<br />
		return -1;<br />
<br />
	return pButtonInfo->nTextLength;<br />
}<br />
<br />
/***********************************************************************\<br />
FUNCTION:			OnSetText<br />
PURPOSE:			Sets the of text of the control<br />
ARGS:				HWND: Handle to the button<br />
RETURN:				None<br />
\***********************************************************************/<br />
<br />
BOOL OnSetText(HWND hWnd, LPCTSTR lpszText)<br />
{<br />
	PBUTTONINFO pButtonInfo = PickButtonInfo(hWnd);<br />
<br />
	int iLen = lstrlen(lpszText);<br />
<br />
	if(iLen > pButtonInfo->nTextLength)<br />
	{<br />
		if(pButtonInfo->szText != NULL)<br />
			free((void *)pButtonInfo->szText);<br />
<br />
		pButtonInfo->szText = (TCHAR *) malloc(iLen + 2);<br />
<br />
		//pButtonInfo->szText = new TCHAR[iLen + 1];<br />
<br />
		if(pButtonInfo->szText == NULL)<br />
			return FALSE;<br />
	}<br />
<br />
	pButtonInfo->nTextLength = iLen;<br />
	ZeroMemory((LPVOID)pButtonInfo->szText, pButtonInfo->nTextLength);<br />
	lstrcpy(pButtonInfo->szText, lpszText);<br />
	<br />
	InvalidateRect(hWnd, NULL, TRUE);<br />
	return TRUE;<br />
<br />
}

Polite Programmer

More Object Oriented then C#

Polite Programmer3-Jun-07 20:01

3-Jun-07 20:01

Ooooooopsssss!
Sorry for that much long message....

Polite Programmer

More Object Oriented then C#

Stephen Hewitt3-Jun-07 20:05

Stephen Hewitt

3-Jun-07 20:05

Follow the steps I gave and odds are the dubugger will take you straight to the source of the problem.

Steve

help with fstream

anbluemoon3-Jun-07 1:24

anbluemoon

3-Jun-07 1:24

can anybody tell me how to read hex number in IDX file (foxpro) by using fstream::read ?

Re: help with fstream

CPallini3-Jun-07 4:02

CPallini

3-Jun-07 4:02

What do you really need to do (hex number is a bit generic, maybe, for instance, a byte, a 16-bit number... Please note: hex is only a number representation base)?

Maybe you need to:

(1) open the stream in binary mode.
(2) use the method read( unsigned char* puch, int nCount ) to get the relevant bytes.

Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

DLL and EXE files

prithaa3-Jun-07 0:43

prithaa

3-Jun-07 0:43

Hello,

I have a set of classes in .h and .cpp files.How can I make dll files and .exe files from them

Prithaa

Christian Graus3-Jun-07 1:14

Christian Graus

3-Jun-07 1:14

Where did they come from ? Did you write them ? You need to create dll and exe projects and then put your code into them.

Christian Graus - Microsoft MVP - C++
Metal Musings - Rex and my new metal blog
"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )

Rajesh R Subramanian3-Jun-07 20:43

Rajesh R Subramanian

3-Jun-07 20:43

Christian Graus wrote:
Where did they come from ?

Nobody can give you wiser advice than yourself. - Cicero

Matthew Faithfull3-Jun-07 1:18

Matthew Faithfull

3-Jun-07 1:18

Are you looking for a compiler? Or wanting to know how to change your build settings to get an EXE as opposed to a DLL? Unsure | :~

Nothing is exactly what it seems but everything with seems can be unpicked.

prithaa3-Jun-07 1:42

prithaa

3-Jun-07 1:42

Hello,
Yes I have made classes through VC++ MFC AppWizard(exe)option in non Doc-View architecture.
Now I want these classes to be used in my another project without actually disturbing the classes.For this purpose if I can make the .dlls and load them in my project directory and #include these .h in my project I think that will be fine.
For now what I do is Add those files in my project through the workspace area and I can actually see all the files in my workspace which I don't want.

Can do like that or I have missed something while making the classes?
Thanks for your replies
Pritaa

Matthew Faithfull3-Jun-07 2:59

Matthew Faithfull

3-Jun-07 2:59

If you've made the classes through the exe AppWizard then it isn't going to be straight forward to try and package them in a Dll. I would suggest starting a new project, An empty Dll that supports/(is linked to) MFC. Then copy the classes you want into it starting with the simplest ones. Then you need to look into exporting the classes from the dll that you want to use. Check this page for a start.
http://msdn2.microsoft.com/en-us/library/3y1sfaz2(VS.71).aspx[^]
I would recommend experimenting a little with creating simple Dlls and using them from simple EXEs before bringing MFC into the picture. Because MFC tries to be a framework it has to assume a 'model' ie EXE or DLL when is generates application classes and the code you get is targetted at one or the other. Things like individual Dialog classes are easy enough to move into a Dll but the main Doc/View classes won't be. Good luck with it anyway Smile | :)

Nothing is exactly what it seems but everything with seems can be unpicked.