Writing file

I use this :
CFile FileName(m_csTemp,CFile::modeCreate | CFile::modeWrite);
to create a file. This expression erase all of the existing files which have the same name. Is there a function which allow to see if a file with the same name already exists ?

Thank's for advance.

Why not you check using an 'if' - 'else' condition before you create the Cfile?
Hope this will help.
Cheers.

How to check ?
if ( what ??? )

1. To determine if a file exists you could use PathFileExists;
2. You could use flag CFile::modeNoTruncate . From MSDN:

Quote:

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Combine this value with modeCreate. If the file being created already exists, it is not truncated to 0 length. Thus the file is guaranteed to open, either as a newly created file or as an existing file. This might be useful, for example, when opening a settings file that may or may not exist already. This option applies to CStdioFile as well.

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Ok, thank's. And if the file already exists, I'd like to enter a new file name...

If you use standard CFileDialog (as "Save as...") or GetSaveFileName API to select the file to write in,
you could use flag OFN_OVERWRITEPROMPT that will

Quote:

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... cause the Save As dialog box to generate a message box if the selected file already exists. The user must confirm whether to overwrite the file.

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Is OFN_OVERWRITEPROMPT explained in MSDN ?
I don't see it...

Have you searched MSDN for it?
My MSDN (october 2000) gives me 16 article having OFN_OVERWRITEPROMPT :wave:
Ok! Have a look at OPENFILENAME structure

It's OK I saw it...

Is that code OK to display a CFileDialog ?

CFileDialog(FALSE,NULL,NULL,OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT,NULL,NULL);
CFileDialog::DoModal;

It doesn't seem to work...

Quote:

---

Is that code OK to display a CFileDialog ?

CFileDialog(FALSE,NULL,NULL,OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT,NULL,NULL);
CFileDialog:: DoModal;

---

Almost... :rolleyes: with some corrections...
I usualy add flag OFN_EXPLORER and test the return value of DoModal:

Code:

---

CFileDialog  cfdlg(FALSE, NULL, NULL, OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT | OFN_EXPLORER,
                    NULL, NULL);
CString strFileName;
int iRet = cfdlg.DoModal();
if(iRet  == IDOK)
{
        //  get selected name:
        strFileName = cfdlg.GetPathName();
}
else
{
        //  error handling
}

---

Ok thank's it works well !
I have a another question. Is there a function "OnClickSave" which allow to do some extra operations when saving?

Which "some extra operations " do you mean?

My question is that when I click on "Save", does the program go on the following line of my program which might be :
CFile FileName(m_csTemp,CFile::modeCreate | CFile::modeWrite);
to create and write my file ?

And if I click "cancel", does it exit from the function it is called from?


For "PathFileExists", is the syntax OK :
if (PathFileExists(csFileName) == TRUE)
{
// Do smthg
}

The calling of this function might not be good cause "Undeclared identifier"...

Quote:

---

My question is that when I click on "Save", does the program go on the following line of my program which might be :
CFile FileName(m_csTemp,CFile::modeCreate | CFile::modeWrite);
to create and write my file ?

And if I click "cancel", does it exit from the function it is called from?

---

I should repeat: you must check the DoModal return value before doing someting else:

Code:

---

CFileDialog  cfdlg(FALSE, NULL, NULL, OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT | OFN_EXPLORER,
                    NULL, NULL);
int iRet = cfdlg.DoModal();
if(iRet  == IDOK)
{
        //  Save button was clicked
        //  get selected name:
        m_csTemp = cfdlg.GetPathName();
        //  now you could work with the selected file:
        CFile FileName(m_csTemp,CFile::modeCreate | CFile::modeWrite);
        .............
}
else // iRet  == IDCANCEL
{
        // Cancel button was clicked
        // you could call the WindowsCommDlgExtendedError function to determine whether an error occurred.
        //  (see MSDN CFileDialog::DoModal )
        ..............
}

---

Quote:

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Originally posted by Jeab.
For "PathFileExists", is the syntax OK :
if (PathFileExists(csFileName) == TRUE)
{
// Do smthg
}

The calling of this function might not be good cause "Undeclared identifier"...

---

Do you have an idea ?

Do you ever read MSDN?

Quote:

---

PathFileExists
Determines if a file exists.

BOOL PathFileExists(
LPCTSTR pszPath
);

Parameters
pszPath
Address of the file to verify.
Return Values
Returns TRUE if the file exists, or FALSE otherwise.

Example
.............
Requirements
Version 4.71 and later of Shlwapi.dll

Windows NT/2000: Requires Windows 2000 (or Windows NT 4.0 with Internet Explorer 4.0 or later).
Windows 95/98: Requires Windows 98 (or Windows 95 with Internet Explorer 4.0 or later).
Header: Declared in shlwapi.h.
Import Library: shlwapi.lib.

---

It means :
a) you must have Internet Explorer 4.0 or later;
b) you must "#include shlwapi.h";
c) you must add shlwapi.lib in your Link "Objecl/Library modules..." settings;

How to recover the address where the files are saved ?



I use this code to open a CfileDialog for "Save as". And I want to see the ".mpg" files:

CFileDialog cfDlg(FALSE, NULL, m_csPCFileName, OFN_NOCHANGEDIR | OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT | OFN_EXPLORER, "*.MPG ", NULL);

But I can't see them...

Any idea ?

try this:

Code:

---

CFileDialog  cfDlg(FALSE, NULL, m_csPCFileName, OFN_NOCHANGEDIR | OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT | OFN_EXPLORER, "Mpg Files (*.MPG)|*.MPG| ", NULL);

---

PS: Please read MSDN. You are not at least trying here !

Quote:

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I use this code to open a CfileDialog for "Save as". And I want to see the ".mpg" files:

CFileDialog cfDlg(FALSE, NULL, m_csPCFileName, OFN_NOCHANGEDIR | OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT | OFN_EXPLORER, "*.MPG ", NULL);

But I can't see them...

---

I am forced to repeat: Do you ever read MSDN?

Quote:

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........
The lpszFilter parameter is used to determine the type of filename a file must have to be displayed in the file list box. The first string in the string pair describes the filter; the second string indicates the file extension to use. Multiple extensions may be specified using ‘;’ as the delimiter. The string ends with two ‘|’ characters, followed by a NULL character. You can also use a CString object for this parameter.

For example, Microsoft Excel permits users to open files with extensions .XLC (chart) or .XLS (worksheet), among others. The filter for Excel could be written as:

static char BASED_CODE szFilter[] =
"Chart Files (*.xlc)|*.xlc|Worksheet Files (*.xls)|*.xls|Data Files (*.xlc;*.xls)|*.xlc; *.xls|All Files (*.*)|*.*||";

---

In your case filter could look like:

Code:

---

szFilter[] =_T("MPG Files (*.MPG)|*.MPG|All Files (*.*)|*.*||");

---

... or only:

CFileDialog cfDlg(FALSE, NULL, m_csPCFileName, OFN_NOCHANGEDIR | OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT | OFN_EXPLORER, _T("MPG Files (*.mpg)|*.mpg||") );


There is no need to declare that static variable.

Thank's it works weel...

Sorry fot all these questions. I've one last:
How is it possible to recover the file path from which the application is executed ?

Check out GetModuleFileName API

Thank's for all of the informations you gave me :)
You really helped me.