CString

Author

122

December 15, 2002 09:54 PM

In a prog I'm making in C++ and MFC, I'm trying to get some simple file i/o done, and I'm using CString, but when I try to save it, the file comes up with no name, but the file extension I used is there (right now it's .dat.) Here's the function thats called when the button is pushed:

    
void CEditorDlg::OnOK() 
{
	m_edit3.GetLine(0,filename); //m_edit3 is the CEdit object that uses the edit box where I get the file name

	CString Stringz(filename);
	int n = Stringz.Insert(555,".dat");

	CFile OutFile(Stringz, CFile::modeCreate | CFile::modeWrite);

	char OutS[20];
	m_edit1.GetLine(0,OutS); //m_edit1 gets a line of text that is to be stored from an edit box

	OutFile.Write(OutS,20);

	OutFile.Close();
}

It compiles fine and makes a file, but the file has no name but it has the .dat extension. Hibiki Wheres the any key? www.geocities.com/dragongames123/home.html INSERT MY OVER-SIZED EXTRAVOGENT PIC HERE: [edited by - HibikiKonzaki on December 15, 2002 10:56:02 PM]

HibikiWheres the any key?www.geocities.com/dragongames123/home.htmlINSERT MY OVER-SIZED EXTRAVOGENT PIC HERE:

mjdalways

122

December 16, 2002 07:05 AM

Do a printf or debug of filename - make sure there is something in the edit box to get.

The Insert(555) looked strange but http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vcmfc98/html/vcrefcstringinsert.asp shows the same example so that should be fine.

However when browsing for GetLine Microsoft does some funky code:

#ifdef _DEBUG
// The pointer to my edit.
extern CEdit* pmyEdit;

int i, nLineCount = pmyEdit->GetLineCount();
CString strText, strLine;

// Dump every line of text of the edit control.
for (i=0;i < nLineCount;i++)
{
pmyEdit->GetLine(i, strText.GetBuffer(pmyEdit->LineLength(i)));
strText.ReleaseBuffer();

strLine.Format(TEXT("line %d: ''%s''\r\n"), i, strText.GetBuffer(0));
afxDump << strLine;
}
#endif

See http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vcmfc98/html/_mfc_cedit.3a3a.getlinecount.asp or http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vcmfc98/html/_mfc_cedit.3a3a.getline.asp

Don''t know why they are doing the GetBuffer/ReleaseBuffer ...

hibikikonzaki

Author

122

December 16, 2002 10:10 PM

Ok, I got it to work. When I changed filename to a local variable, it worked fine.

Also, is there a way to save an int using CFile? I''ve got strings working right, but I can''t find anything on ints. I''m using the docs that came with MSVC++.

Hibiki
Wheres the any key?
www.geocities.com/dragongames123/home.html

INSERT MY OVER-SIZED EXTRAVOGENT PIC HERE:

HibikiWheres the any key?www.geocities.com/dragongames123/home.htmlINSERT MY OVER-SIZED EXTRAVOGENT PIC HERE:

Anonymous

December 16, 2002 10:54 PM

the MS "recommended" way of loading/storing data via a CFile is in conjunction with a CArchive object and the Serialize functions for each loaded/stored CObject-inherited class. the "<<" and ">>" overloaded operators may then be used to load/store any member variables of any given datatype.

  ...CFile fi("skin.ini", CFile::modeCreate |         CFile::modeWrite | CFile::shareDenyWrite);CArchive ar(&fi, CArchive::store);pFileAttributes->Serialize(ar);ar.Close();fi.Close();...

  void CFileAttributes::Serialize( CArchive& ar ){    CObject::Serialize(ar);    if( ar.IsStoring() ) {  // storing code        ar << skin;        ar << name;        ar << type;        ar << author;        ar << attrib;        ar << size;        ar << time_access;        ar << time_create;        ar << time_write;    } else {                // loading code        ar >> skin;        ar >> name;        ar >> type;        ar >> author;        ar >> attrib;        ar >> size;        ar >> time_access;        ar >> time_create;        ar >> time_write;    }}

Hollower

685

December 16, 2002 11:05 PM

Also, is there a way to save an int using CFile? I''ve got strings working right, but I can''t find anything on ints.

It writes numbers like int, float, etc. in binary form. And remember to give it a pointer or use & to get a reference. I know its easy to forget that a string is usually represented by a pointer.

int i;
...
Outfile.Write(&i, sizeof(int));

If you are wanting readable text and not binary you''ll need a function to convert from a number to a string, such as itoa.