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

Waldermort30-Nov-06 6:18

Waldermort

30-Nov-06 6:18

You need to correctly use loops, timers and counters.

It sounds like you are doing all of your drawing directly to the screen, and you have an uncontrolled loop, you should instead be trying draw to an offscreen bitmap. Set a timer, on each timer event bitblt the bitmap to the screen.

Mark Salsbery30-Nov-06 6:27