Unhandled exception: 0xC0000005: Access violation

[promods73]

hi all,
i am new to MFC programming, i am Creating an object of CString to store an filename opened through dialog box.... If i pass this CString object as filename to fopen() function, I am getting Unhandled exception: 0xC0000005: Access violation..... so please help me out in this.....

i.e.
CString Filename;

if( FileDlg.DoModal() == IDOK )
{
Filename = FileDlg.GetFileName();
}


And if i pass this Filename object to fopen() as
fopen(Filename, "r");

When I debug I get the violation exception at this line.....

[Skizmo]

Are you using UNICODE and does fopen support UNICODE filenames ??

btw : You are using MFC, so why use fopen ?? CFile is a better alternative.

[promods73]

i am using this same code of lines in another project... it's working fine......

i am using fopen instead of using CFile class bcoz i am reading it character by character & also byte by byte after some condition..... So can u help me out of this......

[Skizmo]

i am using fopen instead of using CFile class bcoz i am reading it character by character & also byte by byte after some condition..... So can u help me out of this......

Byte by byte is very slow, because this creates a lot of disk access. Personally I would advice you to read the entire file (if it is not TOO big), and process your data in memory.

btw : your crash is a mystery to me. Is there some code in between that uses/modifies the Filename string ? And is the file not locked by something else ?

[cilu]

I suggest having a look on http://www.codeguru.com/forum/showthread.php?t=360659.

[hmc]

char szBuf[BUFLEN];
CString sFilename;

if( FileDlg.DoModal() == IDOK )
{
 sFilename = FileDlg.GetFileName();
 
 CFile file;
 if(file.Open(sFileName, CFile::modeRead))
 {
   DWORD dwSize = file.GetLength();
   if(dwSize < BUFLEN)
    file.Read(szBuf, (UINT)dwSize);
   file.Close();
}

[promods73]

thank you guys.....
i finally got it.......
Actually.. I created same code in another project, and it worked..... I really don't know what is the problem with my Visual Studio 6, so sorry guys for wasting your precious time.