Reg. CSharedFile

Chandra Venkatraman -- chandru@fcpl.co.in
Wednesday, August 28, 1996

Environment:Windows 95, Visual C++ 4.2

I had the oppurtunity to work with MFC's OLE Implementation. I had to
implement a OLE Drop Source and a OLE Drop Target while implementing Drag
and Drop using OLE. Reading one of the samples I came across "CSharedFile"
which was being used by "CacheGlobalData". There was no documentation for
CSharedFile but I assumed it had to be like CMemFile. Is there any specific
reason why CSharedFile is being used while performing "CacheGlobalData".

Is there any place where I can get documentation on CSharedFile

Chandru

		                                  Chandrasekar Venkataraman 
---------------------------------------------------------------------------
Office :
Frontier Computers (P) Ltd.
Vastu Chambers, IInd Floor,
1202/39, Shirole Road,
Shivaji Nagar,
Pune - 411004

Voice : +91 - 0212 - 321536
E-Mail: chandru@fcpl.co.in, vraman@cyberspace.org, csekar@hotmail.com
---------------------------------------------------------------------------

---

Bharat Gogia -- gogiabd@batelco.com.bh
Friday, August 30, 1996

[Mini-digest: 3 responses]

Hi,

This following site will give you documentation you are looking for

http://www.periphere.com/set/sundoc0.htm

Bharat Gogia 

----------
> From: Chandrasekar Venkataraman 
> To: MFC-L 
> Subject: Reg. CSharedFile
> Date: Wednesday, August 28, 1996 8:09 AM
> 
> Environment:Windows 95, Visual C++ 4.2
> 
> I had the oppurtunity to work with MFC's OLE Implementation. I had to
> implement a OLE Drop Source and a OLE Drop Target while implementing Drag
> and Drop using OLE. Reading one of the samples I came across
"CSharedFile"
> which was being used by "CacheGlobalData". There was no documentation for
> CSharedFile but I assumed it had to be like CMemFile. Is there any
specific
> reason why CSharedFile is being used while performing "CacheGlobalData".
> 
> Is there any place where I can get documentation on CSharedFile
> 
> Chandru
> 
> 		                                  Chandrasekar Venkataraman 
>
---------------------------------------------------------------------------
> Office :
> Frontier Computers (P) Ltd.
> Vastu Chambers, IInd Floor,
> 1202/39, Shirole Road,
> Shivaji Nagar,
> Pune - 411004
> 
> Voice : +91 - 0212 - 321536
> E-Mail: chandru@fcpl.co.in, vraman@cyberspace.org, csekar@hotmail.com
>
---------------------------------------------------------------------------

-----From: "Richard A. Nichols" 


Hi Chandru

Environment:Windows 95, Visual C++ 4.2
  

CShared file is in the 4.2 class reference. Below is the description that
is
given. 


CSharedFile is the CMemFile-derived class that supports shared memory
files. Memory files behave like disk files except that the file is stored
in RAM rather than on disk. A memory file is useful for fast temporary
storage or for transferring raw bytes or serialized objects between
independent processes.
Shared memory files differ from other memory files in that memory for them
is allocated with the GlobalAlloc Windows function. GlobalAlloc returns an
HGLOBAL handle rather than a pointer to memory, such as the pointer
returned by malloc. The HGLOBAL handle is needed in certain applications.
For example, to put data on the Clipboard you need an HGLOBAL handle.
CSharedFile objects can automatically allocate their own memory or you can
attach your own memory block to the CSharedFile object by calling
CSharedFile::SetHandle. In either case, memory for growing the memory file
automatically is allocated in nGrowBytes-sized increments if nGrowBytes is
not zero. 
For more information, see the article Files in Programming with MFC and
File Handling in the Run-Time Library Reference.
#include 



Richard A. Nichols
RANWare
-----From: "Ian Carbaugh (Best)" 

CSharedFile uses global memory.  Specifically, "GlobalAlloc(), 
GlobalReAlloc(), GlobalLock(), and GlobalFree() are used instead of the 
alloc/realloc/free memory handlers."  MFC Internals by George Sheppard and 
Scot Wingo discusses this undocumented class.

Ian Carbaugh
Ian_Carbaugh@msn.com

---

| Вернуться в корень Архива |