C / C++ / MFC

28-Nov-01 5:23

Hello,
In the following code, I open a MP3 and read the last 128 bytes of information (to see if the MP3 has a ID3 tag).. This code works fine most of the time.. I click the open button on my app which calls this function.. it works 95% of the time, but every now and then it gives me an error.. "an unnamed file was not found", the file does exist and its in the same directory as all the previous files that I have opened.. if I move or copy the file to another location and try to open it, it opens fine.. weird! Any ideas why??

CFileDialog MP3(TRUE,NULL,NULL,OFN_HIDEREADONLY,"MP3 Files (*.mp3)|*.mp3|");
	
	if(MP3.DoModal() == IDOK)
	{
		strPath = MP3.GetPathName();
		
		ID3TAG.Open(strPath, CFile::modeRead);
		ID3TAG.Seek(-128,CFile::end);
		ID3TAG.Read(tagData,128); //after this line I do a bunch of other stuff with the data..

Thanks,
Rob

Nish Nishant28-Nov-01 5:26

28-Nov-01 5:26

perhaps the file is open by some other process or thread already?

Nish

Sonork ID 100.9786 voidmain
www.busterboy.org
If you don't find me on CP, I'll be at Bob's HungOut

RobJones28-Nov-01 5:38

28-Nov-01 5:38

It shouldn't be open by any other processes. It's on my local machine, I don't have any other apps that are using the file and I don't have any shares open on my PC. I wonder if the strPath string is getting corrupted some how.. I'll do some traces.

If you have any other ideas please let me know.

Thanks!!

Rob

RobJones28-Nov-01 6:35

28-Nov-01 6:35

It appears that the CFile::Seek function is throwing the error.. Any ideas why? It's like it can't find the end of the file. Is there any trouble shooting methods that I can use to determine the cause of the exception?

Thanks again for you help!
Rob

RobJones28-Nov-01 9:19

28-Nov-01 9:19

I don't usually reply to my own msg's but I figured everything out.. so disregard my last few posts..

Thanks,

Rob

28-Nov-01 14:27

Are you sure, that the file is opened properly ???

For a better error description you might use SDK functions CreateFile, ReadFile, CloseHandle and GetLastError instead of mfc.

And perhaps a work-around:
Get the file length, move to byte position (FileLength-128) from start, read the last lines ... But to be honest, I don`t believe that it is the Seek which really causes the trouble here...

Regards, Marco

GetDiskFreeSpaceEx

RickyC28-Nov-01 5:22

RickyC

28-Nov-01 5:22

Hy everyone,

I'm tryng to do an application that show in some window the current amount of memory in the user's hard disc. But when the user is using win 95 before OSR2 the function GetDiskFreeSpaceEx must be replaced by GetDiskFreeSpace, and the MSDN Library tell's me to "you should dynamically link to it via GetProcAddress"... I do everything they tell me to do... but in win 95 my program do not work...
causes an error on kernel32.dll that can't find de GetDiskFreeSpaceExA... please, if someone can help me it's will be great!
I'll post an part of my code that I do the implementation of the MSDN Library:

P_GDFSE pGetDiskFreeSpaceEx = NULL;
pGetDiskFreeSpaceEx = (P_GDFSE)GetProcAddress (GetModuleHandle ("kernel32.dll"),"GetDiskFreeSpaceExA");
if(pGetDiskFreeSpaceEx)
{
fresult = GetDiskFreeSpaceEx (windowsDir,
(PULARGE_INTEGER)&FreeBytesToCaller,
(PULARGE_INTEGER)&TotalBytes,
(PULARGE_INTEGER)&FreeBytes);

m_strDirSistema = _T( windowsDir );
m_dwQuotaLivreUsuario = /*(DWORD*/FreeBytesToCaller / MEGABYTE; // this lines given
- me warnings of conversion but it's work correctly m_dwEspacoTotal = /*(DWORD)*/TotalBytes / MEGABYTE;
m_dwEspacoLivre = /*(DWORD)*/FreeBytes /MEGABYTE;
}
thanks all, for the attention!
cheers!!
and sorry my english, I'm brazilian Smile | :)

Jon Hulatt28-Nov-01 5:47

Jon Hulatt

28-Nov-01 5:47

You say that "MSDN Library tell's" [you to] "dynamically link to it via GetProcAddress"

But in your code, you're trying to dynamically link to GetDiskFreeSpaceExA, not GetDiskFreeSpace.

Sorry to dissapoint you all with my lack of a witty or poignant signature.

Nish Nishant28-Nov-01 5:53

28-Nov-01 5:53

RickyC wrote:
and the MSDN Library tell's me to "you should dynamically link to it via GetProcAddress"...

It does nothin of that sort

It says "To determine whether GetDiskFreeSpaceEx is available, call the LoadLibrary or LoadLibraryEx function to load the KERNEL32.DLL file, then call the GetProcAddress function to obtain an address for GetDiskFreeSpaceEx. If GetProcAddress fails, or if GetDiskFreeSpaceEx fails with the ERROR_CALL_NOT_IMPLEMENTED code, use the GetDiskFreeSpace function instead of GetDiskFreeSpaceEx"

so since you are sure you are on pre-osr2 win 95 dont bother using the GetDiskFreeSpaceEx call and stick to using GetDiskFreeSpace

Nish

Sonork ID 100.9786 voidmain
www.busterboy.org
If you don't find me on CP, I'll be at Bob's HungOut

RickyC28-Nov-01 6:19

RickyC

28-Nov-01 6:19

Hy,
I'm new to MFC... and don't know much...
but in my MSDN Library (january 2001) has something like this:
/*
Use GetDiskFreeSpaceEx if available; otherwise, use
GetDiskFreeSpace.
Note: Since GetDiskFreeSpaceEx is not in Windows 95 Retail, we
dynamically link to it and only call it if it is present. We
don't need to call LoadLibrary on KERNEL32.DLL because it is
already loaded into every Win32 process's address space.
*/
pGetDiskFreeSpaceEx = (P_GDFSE)GetProcAddress (
GetModuleHandle ("kernel32.dll"),
"GetDiskFreeSpaceExA");
if (pGetDiskFreeSpaceEx)
{
fResult = pGetDiskFreeSpaceEx (pszDrive,
(PULARGE_INTEGER)&i64FreeBytesToCaller,
(PULARGE_INTEGER)&i64TotalBytes,
(PULARGE_INTEGER)&i64FreeBytes);
if (fResult)
{

}
}
else
{
fResult = GetDiskFreeSpace (pszDrive,
&dwSectPerClust,
&dwBytesPerSect,
&dwFreeClusters,
&dwTotalClusters);
if (fResult)
{
//some code that I'll not put because the space in this page
}
}

if (!fResult)
printf ("error: %lu: could not get free space for \"%s\"\n",
GetLastError(), argv[1]);
}
I Just try to follow this...
and is not working... sorry if I'm doing something stupid
:\

Michael Dunn28-Nov-01 8:34

Michael Dunn

28-Nov-01 8:34

Download the latest Platform SDK and #include <newapis.h>. That header has wrappers for GetDiskFreeSpaceEx() and other APIs that handle all that linking nonsense for you. Smile | :)

--Mike--
http://home.inreach.com/mdunn/
While I can't be correct on all matters, I can make the reassuring claim that where I am inaccurate, I am at least definitively inaccurate.
Heart | [heart]

your

with

and

Sonork - 100.10414 AcidHelm

Test out a prerelease build of my Hotfix Checker v2.0! (1

jerry0davis19-Mar-02 0:19

jerry0davis

19-Mar-02 0:19

Thanks! I've been looking for something just like this for ages. I just which I'd searched the CP Forums sooner!

Jeremy Davis
http://www.astad.org

Nish Nishant19-Mar-02 0:49

19-Mar-02 0:49

LOL

Now we know why you asked a "how to search the forums" doubt-question in the suggestions forum...

Nish

My miniputt high is now 29
I do not think I can improve on that
My temperament won't hold

www.busterboy.org

jerry0davis19-Mar-02 0:47

jerry0davis

19-Mar-02 0:47

I tried searching the CodeGuru forums and got loads of rubbish, plus "matches" that basically didn't match! Roll eyes | :rolleyes:

Jeremy Davis
http://www.astad.org

Dialog

Peter Liddle28-Nov-01 4:33

Peter Liddle

28-Nov-01 4:33

Hey Guys

I have a dialog form i have made with a tree control in it. I have the dialog box rezizable how do i get the tree control to rezize with the dialog box.

Cheers
Peter

Nish Nishant28-Nov-01 4:35

28-Nov-01 4:35

override OnSize and resize the tree control accordingly

afx_msg void OnSize( UINT nType, int cx, int cy );

Nish

Sonork ID 100.9786 voidmain
www.busterboy.org
If you don't find me on CP, I'll be at Bob's HungOut

Carlos Antollini28-Nov-01 4:36

Carlos Antollini

28-Nov-01 4:36

Add the OnSize Message in your Dialog, in this message you must to change the size of the treectrl...

Best Regards

Carlos Antollini.
Sonork ID 100.10529 cantollini

Peter Liddle28-Nov-01 4:59

Peter Liddle

28-Nov-01 4:59

Cheers Guys

You couldn't also tell me what the function is to rezise the tree control is could you

Cheers
Peter

Nish Nishant28-Nov-01 5:04