Re: EM_EXGETSEL crashes app

From:

"David Ching" <dc@remove-this.dcsoft.com>

Newsgroups:

microsoft.public.vc.mfc

Date:

Sun, 30 Jul 2006 23:34:38 GMT

Message-ID:

<imbzg.74054$fb2.18785@newssvr27.news.prodigy.net>

"Alexander" <the44secs@yahoo.com> wrote in message
news:1154126168.698560.219100@s13g2000cwa.googlegroups.com...

I am trying to retrieve the selected text out of a richedit ctrl in
another app. The following code crashes WordPad (hwnd is a handle to
the control).

CHARRANGE chr = {0};

::SendMessage( hwnd, EM_EXGETSEL, 0, (LPARAM)(CHARRANGE FAR *)&chr );

RichEdit controls in other applications may crash or not but always
return 0 for both chr.cpMin and chr.cpMax despite there being selected
text.

As others have pointed out, the pointer in LPARAM needs to reside in the
same process as the thread that created hwnd (in the WordPad process). I
have created a SendMessageRemote() API which uses VirtualAlloc,
ReadProcessMemory, WriteProcessMemory, and CreateRemoteThread to do the
heavy lifting. It is supported in Win2K/XP only. The code works, but is
not yet ready to be submitted in an article. You can look at it at

http://www.dcsoft.com/private/sendmessageremote.h
http://www.dcsoft.com/private/sendmessageremote.cpp

It is based on a great CodeProject article:
http://www.codeproject.com/threads/winspy.asp.

If anyone can make it better, please feel free.

Thanks,
David