Codejock Developer Community : CXTPSyntaxEditCtrl::OnGetText(WPARAM wBuff

CXTPSyntaxEditCtrl::OnGetText(WPARAM wBuff : Smucker and oleq very thanks....

Mon, 21 Jun 2010 20:46:20 +0000

Author: canyou
Subject: 16846
Posted: 21 June 2010 at 8:46pm

Smucker and oleq very thanks. Your answer is best solution. But, It may have some bug by side effect.

STRNCPY_S(pDest, wBufferSize, (LPCTSTR)pTextData, wBufferSize-1 ); <== It's OK.
STRNCPY_S(pDest, wBufferSize, (LPCTSTR)pTextData, _TRUNCATE); <== It's OK.

And this comment from MSDN :

If truncation behavior is needed, use _TRUNCATE or (size � 1):

strncpy_s(dst, 5, "a long string", _TRUNCATE);

strncpy_s(dst, 5, "a long string", 4);

Thanks. And i hope to fixed SyntaxEditor's bug.

CXTPSyntaxEditCtrl::OnGetText(WPARAM wBuff : Thanks, agree. Please replace...

Mon, 21 Jun 2010 09:21:14 +0000

Author: Oleg
Subject: 16846
Posted: 21 June 2010 at 9:21am

Thanks, agree.

Please replace to
STRNCPY_S(pDest, wBufferSize, (LPCTSTR)pTextData, wBufferSize - 1);

CXTPSyntaxEditCtrl::OnGetText(WPARAM wBuff : Setting wBufferSize to -1 will...

Mon, 21 Jun 2010 09:21:07 +0000

Author: Smucker
Subject: 16846
Posted: 21 June 2010 at 9:21am

Setting wBufferSize to -1 will overrun the buffer. I think this is better, it will keep you from overrunning buffer but return as much as possible:

STRNCPY_S(pDest, wBufferSize, (LPCTSTR)pTextData, _TRUNCATE);

CXTPSyntaxEditCtrl::OnGetText(WPARAM wBuff : I tested this case using by MDITextEditor...

Mon, 21 Jun 2010 03:29:35 +0000

Author: canyou
Subject: 16846
Posted: 21 June 2010 at 3:29am

I tested this case using by MDITextEditor Application.

First testcase........................

1. void CMDITextEditorView::OnReadOnly() {

TCHAR buffer[255];
GetEditCtrl().GetWindowText( buffer, 255 ); // <== This code generated event, [CXTPSyntaxEditCtrl, ON_MESSAGE(WM_GETTEXT, OnGetText)]

}

2. Compile and App execution

3. write text at editor( more than 256 Char )

4. Execute Testing Code

=> Application Menu > Edit > Read Only

5. This case application died.

LRESULT CXTPSyntaxEditCtrl::OnGetText(WPARAM wBufferSize, LPARAM lpBuffer) {

...

STRNCPY_S(pDest, wBufferSize, (LPCTSTR)pTextData, wBufferSize); // died this code => _RETURN_BUFFER_TOO_SMALL(_DEST, _SizeInBytes);

...

}

Is this case USER FAULT or Bad Code???

Second testcase........................

I changed only first step.

1. void CMDITextEditorView::OnReadOnly() {

TCHAR buffer[255];
GetEditCtrl().GetWindowText( buffer, 200); // <== This code generated event, [CXTPSyntaxEditCtrl, ON_MESSAGE(WM_GETTEXT, OnGetText)]

}

Application died like first testcase.

So, i'm finding solution.

[1] LRESULT CXTPSyntaxEditCtrl::OnGetText(WPARAM wBufferSize, LPARAM lpBuffer)

{

if (wBufferSize == 0)
return OnGetTextLen(0, 0);

wBufferSize = -1; // <== add this code, so..application not died. very big size buffer

.............

}

[2] LRESULT CXTPSyntaxEditCtrl::OnGetText(WPARAM wBufferSize, LPARAM lpBuffer)

{

.............

//STRNCPY_S(pDest, wBufferSize, (LPCTSTR)pTextData, wBufferSize); // <== Not use this code.

_tcsncpy(pDest, (LPCTSTR)pTextData, wBufferSize);

}

can be solution ?

CXTPSyntaxEditCtrl::OnGetText(WPARAM wBuff : This function is called when i...

Mon, 21 Jun 2010 01:33:28 +0000

Author: canyou
Subject: 16846
Posted: 21 June 2010 at 1:33am

This function is called when i selected some string in editor. => ON_MESSAGE(WM_GETTEXT, OnGetText), CXTPSyntaxEditCtrl::OnGetText

That may be system call.

So, i think..that function have some unstable code.

For example, wBufferSize > tcslen(lpBuffer)

WPARAM wBufferSize = 255;

TCHAR lpBuffer= new TCHAR[200];

SendMessage( WM_GETTEXT, wBufferSize, lpBuffer);

LRESULT CXTPSyntaxEditCtrl::OnGetText(WPARAM wBufferSize, LPARAM lpBuffer) {

LPTSTR pDest = (LPTSTR)lpBuffer;
STRNCPY_S(pDest, wBufferSize, (LPCTSTR)pTextData, wBufferSize); // <== died 'Buffer Too Small'

}

How can i exception handling about this error?

Is this user fault ? I want to handling this error.

CXTPSyntaxEditCtrl::OnGetText(WPARAM wBuff : Hi, Try to pass larger buffer...

Fri, 18 Jun 2010 06:36:29 +0000

Author: Oleg
Subject: 16846
Posted: 18 June 2010 at 6:36am

Hi,
Try to pass larger buffer and larger wBufferSize.

CXTPSyntaxEditCtrl::OnGetText(WPARAM wBuff : What is this function?? LRESULT...

Fri, 18 Jun 2010 05:42:03 +0000

Author: canyou
Subject: 16846
Posted: 18 June 2010 at 5:42am

What is this function??

LRESULT CXTPSyntaxEditCtrl::OnGetText(WPARAM wBufferSize, LPARAM lpBuffer)

In my desktop, MDITextEditor.exe died in this code.
If i selected some string, died App.
In the callstack........

STRNCPY_S(pDest, wBufferSize, (LPCTSTR)pTextData, wBufferSize);

#if (_MSC_VER > 1310) // VS2005
_tcsncpy_s(strDestination, sizeInWords, strSource, count);

died this code => _RETURN_BUFFER_TOO_SMALL(_DEST, _SizeInBytes);

Please help me.!!! Thanks.