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Re: In MFC using a MS Access Database will NOT allow more Tahn 255 Chars even with setting RFX_Text to 1024 length

Larry Mills Sr15-Dec-09 14:28

Larry Mills Sr

15-Dec-09 14:28

But doesn't all the data fields(columns) have to be in binary? Could you please send me an example of how to do that.

A C++ programming language novice, but striving to learn

Re: In MFC using a MS Access Database will NOT allow more Tahn 255 Chars even with setting RFX_Text to 1024 length

David Crow15-Dec-09 3:04

David Crow

15-Dec-09 3:04

Larry Mills Sr wrote:
I cannot get the MS Access Database to accept over 1000 chars into a column using the RFX_Text that is set to 1024 length (See Previous Post CMyDB.cpp RXF listing).

Unless the maximum was increased in Access 2007, the limit for Text fields is 255. With a memo field, you can store up to 65535 characters.

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Re: In MFC using a MS Access Database will NOT allow more Tahn 255 Chars even with setting RFX_Text to 1024 length

Larry Mills Sr15-Dec-09 14:27

Larry Mills Sr

15-Dec-09 14:27

Yess, David,   it is still 255. My field is set to Memo rather than text. but still it is NOT accepted by the Access DB; though eactly 918 chars was there before the Update() was called.

long nMaxLength = 1024;
     RFX_Text(pFX, _T("[Instructions]"), m_Instructions,nMaxLength);// 918 chars loaded

Less than 255 loaded into DB!!!

I have no idea why this is happening.

David A question nfor you personally: Was you ever able to setup the Edit() and Delete() functions in your program you sent me?   Let me know if/when you have this.

Thanks.

A C++ programming language novice, but striving to learn

Re: In MFC using a MS Access Database will NOT allow more Tahn 255 Chars even with setting RFX_Text to 1024 length

David Crow16-Dec-09 3:40

David Crow

16-Dec-09 3:40

Larry Mills Sr wrote:
David A question nfor you personally: Was you ever able to setup the Edit() and Delete() functions in your program you sent me? Let me know if/when you have this.

I've not forgotten. When I got back from my break, I had a bunch of Java/DBCS issues to resolve for our Japanese folks.

Copying files from an archive

Code-o-mat14-Dec-09 12:02

Code-o-mat

14-Dec-09 12:02

Hello folks!

A theoretical question in 2 parts:
1. is it possible to copy files to which i have only an ID list (so no "text representation" of the path like "c:\folder\file" and i can't get one either)? I mean something like SHFileOperation[^] but with IDL's, not paths.
2. If it is possible, would this work on files inside an archive. I mean, -let's say- i have the ID list to a file that is compressed inside a ZIP archive (you can get this by asking for an enumerator from the shell interface object that represents the ZIP archive and then enumerating the files, however, trying to convert this ID list into a path seems to fail). Could i copy this file using the method mentioned in question 1 to some other location and "trust" the shell to perform the required uncompression and such "invisibly"?

Or a different aproach: is it possible to get a valid path to a file compressed into an archive that the shell can process, i mean something like "c:\folder\compressed_archive.zip\file_inside_archive.ext"? As i said in part 2, one seems to be able to get the ID list to "file_inside_archive.ext", but SHGetPathFromIDList[^] won't take it.

Thanks in advance for any suggestions or ideas.

> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Sometimes you just have to hate coding to do it well. <

Re: Copying files from an archive

David Crow15-Dec-09 3:10

David Crow

15-Dec-09 3:10

Code-o-mat wrote:
1. is it possible to copy files to which i have only an ID list (so no "text representation" of the path like "c:\folder\file" and i can't get one either)?

Would SHGetPathFromIDList() help?

Re: Copying files from an archive

Code-o-mat15-Dec-09 3:20

Code-o-mat

15-Dec-09 3:20

Thanks for the reply!

Sadly, as i said in my post, SHGetPathFromIDList fails on IDLs of zipped files. The documentation says SHGetPathFromIDList works only on file-system objects, i guess a file compressed into an archive is no longer considered part of the filesystem, it's rather something like a virtual item.

Since i am able to look into a compressed archive and copy-paste or drag-drop items out of it in explorer my guess is that getting the shell to do the dirty work of uncompressing the files to some location should be possible. Maybe faking a drag-drop could work...i will do some research into this once i get some free time to do so.

> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Sometimes you just have to hate coding to do it well. <

A solution

Code-o-mat15-Dec-09 10:55

Code-o-mat

15-Dec-09 10:55

So in case anyone ever reads this and is curious about the result, i did the experimenting and as it seems the drag-drop "emulation" works, i used GetUIObjectOf[^] method to get an IDataObject for the "virtual" file inside the archive, i used the same method to get an IDropTarget for the folder i wanted to copy the file into and then i called DragEnter, DragOver (this is probably not needed) and Drop of IDropTarget, specifying the IDataObject i got and DROPEFFECT_COPY. This seems to do the job, the shell moves the file from the archive into the target folder. Thumbs Up | :thumbsup:

> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Sometimes you just have to hate coding to do it well. <

problem with using MUTEX events

Alan Kurlansky14-Dec-09 10:43

Alan Kurlansky

14-Dec-09 10:43

In my VS c++ console app i have the main thread processing input obtained by other secondary threads. The secondary threads use WaitForSingleObject to wait on either tcp input or wait to get the mutex back. These mutexes are used to control access to global buffers. Each secondary thread writes to a specific global buffer and when complete gives up the mutex. The main thread uses WaitForMultipleObjects to determine which buffer to read from, then, when done, turns the mutex back over to the secondary thread.

Problem is if the apps start up when there's a lot of data(messages) backed up I initially get a lot of reported empty buffers in the beginning and later when I get buffers they (the corresponding mutex) seem to be ignored by the main thread. This is what my log file shows. It may be that even my log file sequencing is questionable at this point.
Starting the processes like this would not be the norm but still it should all work even under these conditions.
Is it possible I have some kind of synchronization problem between the main and secondary threads? More details provided upon request.
Thanks

Re: problem with using MUTEX events

Migounette14-Dec-09 11:53

Migounette

14-Dec-09 11:53

More information is needed in order to help you.
A common error when we use WaitForMultipleObject is the bWaitAll is not set correctly or an invalid handled is passed to the function.

Check this, if none of the above answers correspond to your issue.

Please provide us more information

Re: problem with using MUTEX events

Alan Kurlansky15-Dec-09 3:09

Alan Kurlansky

15-Dec-09 3:09

Thanks for the hints. I created the threads as follows:
HANDLE   mutexFIXHandle;
HANDLE   mutexSetAlertTimer;
HANDLE     mutexSetAWAYHandle;
mutexFIXHandle     = CreateMutex(NULL, false, NULL);
mutexSetAlertTimer = CreateMutex(NULL, false, NULL);
mutexSetAWAYHandle = CreateMutex(NULL, false, NULL);

Based on first reply I changed this to and will retest:

mutexFIXHandle     = CreateMutex(SYNCHRONIZE, false, NULL);
mutexSetAlertTimer = CreateMutex(SYNCHRONIZE, false, NULL);
mutexSetAWAYHandle = CreateMutex(SYNCHRONIZE, false, NULL);
   //
   // for waitformutlipleobjects
   //
HANDLE ghEvents[3];
ghEvents[0] =     mutexFIXHandle;
ghEvents[1] =     mutexSetAlertTimer;
ghEvents[2] =     mutexSetAWAYHandle;
The skeleton of the WaitForMultipleObjects looks like this:
while (1) {
   waitRval =   WaitForMultipleObjects( 3, ghEvents, FALSE,   2000);

     if (waitRval == WAIT_OBJECT_0) {
                     // process event
                     ReleaseMutex(mutexFIXHandle);
            }
            else if (waitRval == (WAIT_OBJECT_0 + 1) ) {
                     // process event
                     ReleaseMutex(mutexSetAlertTimer);
            }
            else if (waitRval == (WAIT_OBJECT_0 + 2) ) {
                        // process event
                        ReleaseMutex(mutexSetAWAYHandle);
            }
            else if (waitRval == WAIT_TIMEOUT) {
                     //printf("Wait timed out\n");
            }
            else {
                     // log something
            }
}

Re: problem with using MUTEX events

Alan Kurlansky15-Dec-09 3:23

Alan Kurlansky

15-Dec-09 3:23

I also needed to do this to get it to compile:
mutexFIXHandle = CreateMutex((LPSECURITY_ATTRIBUTES)SYNCHRONIZE, false, NULL);
mutexSetAlertTimer = CreateMutex((LPSECURITY_ATTRIBUTES)SYNCHRONIZE, false, NULL);
mutexSetAWAYHandle = CreateMutex((LPSECURITY_ATTRIBUTES)SYNCHRONIZE, false, NULL);

Re: problem with using MUTEX events

Alan Kurlansky15-Dec-09 3:55

Alan Kurlansky

15-Dec-09 3:55

Using (LPSECURITY_ATTRIBUTES)SYNCHRONIZE causes the program to crash. So I'm back to using NULL.

Playing an AVI video from memory

zzelephant14-Dec-09 10:10

zzelephant

14-Dec-09 10:10

Hello,

I need to integrate a video player / video API into my MFC / C++ application. It needs to be able to take video data stored as byte arrays in memory and display it in a preview window.

Is DirectShow the appropriate framework to use for this? As far as I have been able to tell, I would need to write a custom source filter which appears to be non trivial.

Is there a simpler way to do this?

Thanks!

akhtar nasary14-Dec-09 8:45

akhtar nasary

14-Dec-09 8:45

hi my name is akhtar gul <small><pre><code> D'Oh! | :doh:

Re: hi

loyal ginger14-Dec-09 9:05

loyal ginger

14-Dec-09 9:05

Your first message is pretty hard to comprehend.

Re: hi

CPallini14-Dec-09 10:14

CPallini

14-Dec-09 10:14

Hi Akhtar,
What is your problem? The name?
Smile | :)

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-- Alfonso the Wise, 13th Century King of Castile.

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[My articles]

Split images into several regions.

franckesh14-Dec-09 5:06

franckesh

14-Dec-09 5:06

Hi,
I would like to compare some (black& white) images region by region. I want to know how to split an image into many regions with Qt.

franck

Re: Split images into several regions.

Tim Craig14-Dec-09 14:23

Tim Craig

14-Dec-09 14:23

As far as I know, Qt is a GUI framework and not an imageprocessing library. If you're looking for a lot of image processing functions, try OpenCV.

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How to control LEDs using Parallel Port and Turbo C?

--xtiAN_002--14-Dec-09 3:53

--xtiAN_002--

14-Dec-09 3:53

Hello to everyone!

I need some help. How can I control 8 LEDs using parallel port and Turbo C? I have read this article http://www.codeproject.com/KB/cs/csppleds.aspx but it is written in C# language and since I only know C language, I don't know how to program it.

Please help me for the source code in Turbo C. Any help will higly appreciated. Thanks in advance.

Re: How to control LEDs using Parallel Port and Turbo C?

transoft14-Dec-09 4:35

transoft

14-Dec-09 4:35

Using following function to load the dll.

HMODULE hUsbLib = LoadLibrary("inpout32.dll");

GetProcAddress(hUsbLib, "Output");

Rect

kumar sanghvi14-Dec-09 2:29

kumar sanghvi

14-Dec-09 2:29

HI,
Is it possible to draw rect using Normalised coordinates like 0.399567,0.000000,1.000000,0.399369

Re: Rect

CPallini14-Dec-09 2:56

CPallini

14-Dec-09 2:56

GDI+ allows this. Anyway why bother? Simply properly scale the rectagle before drawing it.
Smile | :)

Re: Rect

kumar sanghvi14-Dec-09 17:39

kumar sanghvi

14-Dec-09 17:39

pls let me know how can i do that...

Re: Rect

loyal ginger14-Dec-09 18:02

loyal ginger

14-Dec-09 18:02

GDI+ uses floating point coordinates. You just need to use GDI+.

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