C / C++ / MFC

4-Jan-10 1:32

Hi,
I have used CComPtr class to declear two IStream type variable like below:

CComPtr<IStream> m_pStream;
CComPtr<IStream> m_pStream2;

and some where in my code I Create a stream on a file and let my m_pStream variable point at it like below:

::SHCreateStreamOnFileW(FileName,STGM_READWRITE | STGM_SHARE_DENY_WRITE,&pStream);

Now I want to do sth cause the first Stream variable "m_pStream" release the specified File, so I could create the stream on the same file and let my secound Stream variable m_pStream2 points at it like below:

::SHCreateStreamOnFileW(FileName,STGM_READWRITE | STGM_SHARE_DENY_WRITE,&pStream2);

because my Stream vars are defined with CComPtr class I coudn't use the Release method of my Stream variables.
even I have tested nullifying the first Stream variable but it didn't solve my problem.

What should I do?

KarstenK4-Jan-10 1:57

4-Jan-10 1:57

use detach or different scope for the streams

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Greetings from Germany

A&Ms4-Jan-10 3:27

4-Jan-10 3:27

would you please explain it more I couldn't find any thing. a little code would be useful
and there is no detach method

KarstenK4-Jan-10 3:34

4-Jan-10 3:34

CComPtr::Detach()

http://msdn.microsoft.com/en-us/library/w200fbea%28VS.80%29.aspx[^]

Press F1 for help or google it.
Greetings from Germany

A&Ms4-Jan-10 4:42

4-Jan-10 4:42

for m_pStream->Detach(); I got the following Error:

Error	1	error C2039: 'Detach' : is not a member of 'ATL::_NoAddRefReleaseOnCComPtr<T>'

Even I taype cast my CComPtr to CComPtrBase but again there were only to Member functions which both were in private scope! Confused | :confused:

KarstenK4-Jan-10 20:35

4-Jan-10 20:35

Casting is absolutitly no solution for this problem!!!

use different scope for both variables

Press F1 for help or google it.
Greetings from Germany

Stephen Hewitt4-Jan-10 3:13

Stephen Hewitt

4-Jan-10 3:13

Amir_m wrote:
because my Stream vars are defined with CComPtr class I coudn't use the Release method of my Stream variables.

CComPtr has a Release[^] method. Use . ***NOT*** ->: pStream.Release();

Steve

A&Ms4-Jan-10 3:29

4-Jan-10 3:29

of course I know But The Release Method of CComPtr Class is a private method and compiler does not let me to use it.

Stephen Hewitt5-Jan-10 3:54

Stephen Hewitt

5-Jan-10 3:54

Amir_m wrote:
of course I know But The Release Method of CComPtr Class is a private method and compiler does not let me to use it.

No, it's not private. The following compiles fine:

CComPtr<IStream> spStream;
spStream.Release();

Steve

KingsGambit4-Jan-10 18:16

KingsGambit

4-Jan-10 18:16

May be you can try as follows:

void Foo()
{
  {
    CComPtr<IStream> m_pStream;
    ::SHCreateStreamOnFileW(...);
  }

  {
   CComPtr<IStream> m_pStream2;
   ::SHCreateStreamOnFileW(...);
  }
}

A&Ms4-Jan-10 18:50

4-Jan-10 18:50

My Problem is accessing the file because the Stream Created previously doesn't release the file I can't access the file with another stream (even nullifying that stream doesn't cause it to release the file)

User permission problem with MFC

KingsGambit4-Jan-10 19:09

KingsGambit

4-Jan-10 19:09

In the code segment in my previour post, m_pStream and m_pStream2 are in different scopes (between {}), so the streams will be closed automatically when the scope ends. So, both calls to SHCreateStreamOnFile(...) will be successfull.

bhanu_85094-Jan-10 0:38

bhanu_8509

4-Jan-10 0:38

Dear All,

I have developed an application in MFC and it is working fine and creating directories and file in the program files directory when the program is run as administrator. But when the program is run as limited user account, the program cannot write any files in the program files directory.

The same application developed in JAVA seems to be working fine in both Admin user and limited user. When I googled, all articles recommends to create the files under Application Data for all users. But, for me changing this will be a huge task. Is there any other alternative to grant access to the limitied account user from my application.

Many thanks in advance.

Bhanu

CPallini4-Jan-10 1:02

CPallini

4-Jan-10 1:02

bhanu_8509 wrote:
The same application developed in JAVA seems to be working fine in both Admin user and limited user.

So, why don't you use that one (just kidding...)? Big Grin | :-D

This may be useful [^].
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.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

[My articles]

KarstenK4-Jan-10 2:01

4-Jan-10 2:01

check that the work of the Java-App isnt virtualized.

It isnt the right way to create some directories in the prog dir, if it isnt a installation. Better use the user-dirs

Press F1 for help or google it.
Greetings from Germany

bhanu_85094-Jan-10 5:32

bhanu_8509

4-Jan-10 5:32

If I use the All Users/Application Data/ directory then the files created by Administrator cannot be overwrite by the Limited account user.

Please help me.

KarstenK4-Jan-10 20:38

4-Jan-10 20:38

user data belongs in the user directorys.

If it are global settings than the admin can also write them in the registry.

Is is an architectual issue Unsure | :~

Press F1 for help or google it.
Greetings from Germany