C / C++ / MFC

the use of CreateNewDocument or ID_FILE_NEW

1-Dec-06 6:09

TheDelChop wrote:
but is that what is most likely causing error?

Actually I thought that might be the case, since you stated you had other similar working apps.

Looking at your code again this morning, though, I would try changng this line:

SetClassLong(mainWnd,GCL_HICON,IDI_EXE);

to

SetClassLong(mainWnd,GCL_HICON,LoadIcon(hInstance, MAKEINTRESOURCE(IDI_EXE));

prithaa30-Nov-06 7:57

prithaa

30-Nov-06 7:57

Hello,

If I want to open a new document through the document view architecture but not through the File New option .Is there any way out.

How can I add a message handler to an object-ID so that it enables me to open a new document and then pass parameters to CDocument.

Prithaa

A Question about CreateFile [modified]

Findekano30-Nov-06 5:03

Findekano

30-Nov-06 5:03

Hi guys -

I have a question about using Windows API Create():

I use this API to create a file by using parameter FILE_FLAG_DELETE_ON_CLOSE, since I want it automatically been deleted when it is been closed, the codes like below:

HANDLE handle = ::CreateFile(
    _T("d:\\test.txt"),
    GENERIC_WRITE,
    FILE_SHARE_DELETE | FILE_SHARE_READ,
    NULL,
    CREATE_ALWAYS,
    FILE_ATTRIBUTE_TEMPORARY | FILE_FLAG_DELETE_ON_CLOSE,
    NULL);

After I create the file I will write some information into it, of course. And the file will get deleted when it is closed -- so far so good.

In another process I will need to open this file to get the information I wroted in. I also uses CreateFile() to test if the file exists. However I always got a access violation when accessing to the file. A simple test case will be open d:\test.txt using notepad, it will tell you that the file is opened by another process. GetLastError always return a error 32 afterwise.

Here is what I see from MSDN:

>>>
FILE_FLAG_DELETE_ON_CLOSE
The system deletes a file immediately after all of its handles are closed, which includes the specified handle and any other open or duplicated handles.
If there are existing open handles to a file, the call fails unless they were all opened with the FILE_SHARE_DELETE share mode.

Subsequent open requests for the file fail, unless the FILE_SHARE_DELETE share mode is specified.
<<<

You can find from the code listed above, I *DO* have FILE_SHARE_DELETE specified. Why I still can not the file opened in another process?

Any suggestion or comments are greatly appreciated!

Cheers,
Jay

-- modified at 11:09 Thursday 30th November, 2006

Mark Salsbery30-Nov-06 5:38

30-Nov-06 5:38

Findekano wrote:
In another process I will need to open this file to get the information I wroted in.

Can you post the code for CreateFile() in the process that reads from the file?

Mark

Jay Zhu30-Nov-06 14:37

Jay Zhu

30-Nov-06 14:37

It is just an ordinary call..nothing special:

HANDLE hHandle = CreateFile(strFile,
                            GENERIC_READ,
                            FILE_SHARE_READ|FILE_SHARE_WRITE,
                            NULL,
                            OPEN_EXISTING,
                            FILE_ATTRIBUTE_NORMAL,
                            NULL);

Jay Zhu@Shanghai, China

Mark Salsbery30-Nov-06 14:50

30-Nov-06 14:50

First off, you didn't allow shared write access when opening the original file.

Try using FILE_SHARE_READ|FILE_SHARE_WRITE|FILE_SHARE_DELETE for the share mode on both CreateFile()
calls.

Limited string size in CStatusBarCtrl

Jay Zhu30-Nov-06 16:58

Jay Zhu

30-Nov-06 16:58

It works! Thanks man!

Jay Zhu@Shanghai, China

stupendous@mail.ru30-Nov-06 5:02

stupendous@mail.ru

30-Nov-06 5:02

Hi everyone.

Here is how I use CStatusBarCtrl in my dialog:

In OnInitDialog()

m_StatusBarCtrl.Create(WS_CHILD|WS_VISIBLE|CCS_BOTTOM|SBARS_SIZEGRIP,<br />
    CRect(0,0,0,0), this, IDC_STATUS_BAR);<br />
<br />
     int widths[1] = {-1};<br />
<br />
     m_StatusBarCtrl.SetParts(1, widths);<br />

In OnSize()

<br />
m_StatusBarCtrl.SendMessage( WM_SIZE, 0, 0 );<br />

And when I need to update status, I invoke:

<br />
void CMyDlg::UpdateStatusBar(const std::string& in_rsNewStatus)<br />
{<br />
  m_StatusBarCtrl.SetText(in_rsNewStatus.c_str(), 0, 0);<br />
 <br />
}

But if the string is long enough, it is cut even when current StatusBar's size is able to encapsulate it! What is strange, is that it is cut differently: I mean, that number of letters, that are shown and the length of shown string in pixels are not equal for different strings.

Has anybody come across the same?

Re: Limited string size in CStatusBarCtrl

Mark Salsbery30-Nov-06 6:38

Re: Limited string size in CStatusBarCtrl

30-Nov-06 6:38

Are you sure you need to forward WM_SIZE messages to a CStatusBar control?
Have you tried NOT sending WM_SIZE to the control?

Mark

Steve Echols30-Nov-06 11:42

Steve Echols

30-Nov-06 11:42

According to the documentation for SB_SETTEXT on msdn, "The text for each part is limited to 127 characters."

- S
50 cups of coffee and you know it's on!

HELP! HELP! How can I send SNMP packet & retrieve them

ATC30-Nov-06 4:52

Re: HELP! HELP! How can I send SNMP packet & retrieve them

30-Nov-06 4:52

I am working with an equipment that only can be configuration through local Network! It use SNMP protocol (with UDP for parsing data). Anyone knows how to work with it? Cry | :((

Note: I did try the ServerSocket_Demo in this site, but it not the same. Because it only try to send information in TCP (or UDP) ... but not in SNMP. The result is: The equipment rejected both ways

Thanks to any help D'Oh! | :doh:

Mark Salsbery30-Nov-06 5:51

Re: HELP! HELP! How can I send SNMP packet & retrieve them

30-Nov-06 5:51

Do you know the SNMP Protocol[^]?

ATC30-Nov-06 6:10

Re: HELP! HELP! How can I send SNMP packet & retrieve them

30-Nov-06 6:10

I have learned about it, but the problem for me now is: Even I understand smome thing about it:

. Packet Info: (ie: packet length ...)
. Ethernet - II (ie: IPv4)
. IP (ie: version, source, destination, protocol ... checksum)
. UDP (ie: source, destination, protocol ... checksum)
. Extra data (...)
. FCS (...)

I still does not know how to imply in my VC++ program in order to link correctly with the equipment (Send/Receive SNMP packets)

Can you help?

Mark Salsbery30-Nov-06 6:17

Re: HELP! HELP! How can I send SNMP packet & retrieve them

30-Nov-06 6:17

I have never used the protocol but since it works over tcp/ip I would imagine you can send/recv
SNMP packets using sockets.

Do you need to know how to use sockets from C++?

Mark

ATC30-Nov-06 7:36

Re: HELP! HELP! How can I send SNMP packet & retrieve them

30-Nov-06 7:36

In VC++ ... yes, if it can send SNMP packets as I described

Thanks

Mark Salsbery30-Nov-06 7:48

Re: HELP! HELP! How can I send SNMP packet & retrieve them

30-Nov-06 7:48

It looks like you have some studying to do...

Windows Sockets 2[^]

Maybe look around MSDN or Google and see if there's higher-level APIs or libraries for working
with SNMP. EVerything you need to know is documented somewhere Smile | :)

ATC30-Nov-06 8:28

A better Sleep() function

30-Nov-06 8:28

Hi Mark,

Thanks for the usefull links. I will work on it immediately Big Grin | :-D

Johpoke30-Nov-06 4:23

Johpoke

30-Nov-06 4:23

Ive been using Sleep() alot, but now i need something with smaller units, like microseconds or something. Ive used while loops that count a couble hundred, but there must be some more cpu friendly way to sleep a few microseconds?

any ideas?

maybe i could use timer? does it go down to that unit? if so how would i use that?

thanks

/Johannes

/Johannes

David Crow30-Nov-06 4:52

David Crow

30-Nov-06 4:52

Johpoke wrote:
Ive been using Sleep() alot...

Why? What is it about your application that requires the (over)use of this function?

"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15

"Judge not by the eye but by the heart." - Native American Proverb

James R. Twine30-Nov-06 5:00

James R. Twine

30-Nov-06 5:00

Look up "Multimedia timers" in MSDN for more high-resolution timers. But I agree with DC's post... It might be worth looking into why you are using Sleep(...) so much. Excessive use of Sleep(...) is often (although not always) a sign of a larger problem.

Peace!

-=- James

If you think it costs a lot to do it right, just wait until you find out how much it costs to do it wrong!
Avoid driving a vehicle taller than you and remember that Professional Driver on Closed Course does not mean your Dumb Ass on a Public Road!
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Johpoke30-Nov-06 5:09

Johpoke

30-Nov-06 5:09

My program draws fireworks, no sleep and they whiiiz by abit fast,

Ille look into the multimedia timers!

thanks

/Johannes

benjymous30-Nov-06 5:23

benjymous

30-Nov-06 5:23

Work out how much time has passed since your last frame, then you can scale up your animation to update accordingly

--
Help me! I'm turning into a grapefruit!

Johpoke30-Nov-06 5:57

Johpoke

30-Nov-06 5:57

Um?

it uses SetPixel for everything..

/Johannes