Save button MFC

[kacaka]

hi guys nid some help here



For the save button i was suppose to save my input into a text file.And i was suggested by my friends to use append so that when i typed in a new input the old input wouldnt get deleted,so hw shall i go about doing this.

Before that i was using CFile but my friend said that CFile doesnt have an append function so my old input would get deleted.

THis is my old code for reference.

void CFileProcDlg::OnBnClickedSaveBtn()
{
// TODO: Add your control notification handler code here
this->UpdateData();

CFile f;

char strFilter[] = { "TXT Files (*.txt)|*.txt|All Files (*.*)|*.*||" };

CFileDialog FileDlg(FALSE, ".txt", NULL, 0, strFilter);

if( FileDlg.DoModal() == IDOK )
{
f.Open(FileDlg.GetFileName(), CFile::modeCreate | CFile::modeWrite);
CArchive ar(&f, CArchive::store);

ar << m_Date << m_Time << m_File ;
ar.Close();
}
else
return;

f.Close();



ps. im using MFC vs 2005

[sunny_sz]

To achieve your goal, try

#include <fstream.h>          //Needed to create output file

void main()
{
     ofstream File;               //Names File as ofstream (for output to file)
     File.open("File.txt",ios::out);     //Opens "File.txt" for output
     
     File << "This is the first line.\n";     //Outputs to file
     File << "This is line two.";               //Outputs to file
     File << " This is still on line two.\n";//Outputs to file
     File.close();                                   //Closes file
     
     File.open("File.txt",ios::app);               //Reopens file to append, if you just used ios::out again, it would erase everything and rewrite the file
     File << "This is appending the text file. This is line 3.\n"; //Outputs to file
     File << "And finally line 4!\n";     //Outputs last line of file
     File.close();                              //Closes opened file
}

[kacaka]

hi ,sorry i am noob..where am i suppose to type tis code at?and i use edit boxes to type the data into,so how shld i let it allow to take the data from the edit box and store into the text file and also append.

[kacaka]

sorry but just want to ask does the code works in microsoft foundation class 2005? my friend suggest using the fopen fuction as it has append fuction.

[GCDEF]

Your friend is wrong. To append to a file using CFile simply call SeekToEnd() after opening the file for writing.

[GCDEF]

Just looked at your code. Why are you using a CArchive object to write to a text file?

[kacaka]

so where am i suppose to include the line in my program.
and im suppose to key in data into the 3 edit boxes,den save them into a text file,so how do i
add the edit boxes into the code?


sorry for asking so much and thanks for all that help .

[VictorN]

1. create control member variables for all your edit boxes
2. use CWnd::GetWindowText to read in texts from edit controls to some CString objects
3. use CStdioFile::WriteString to write these CStrings to the file

[kacaka]

hi may i know hw to code the 2nd one if i have m_Date and m_Time which i had set the control on

[VictorN]

If m_Date and m_Time are the control member variables (of the type CEdit or any CEdit derived class) then:

CString strTextDate;
m_Date.GetWindowText(strTextDate);
CString strTextTime;
m_Time.GetWindowText(strTextTime);

[Elrond]

Another thing:

If you want to open the file to append text without deleting the content, you need to use the CFile::modeNoTruncate flag:

CStdioFile file;
file.Open(filename, CFile::modeCreate | CFile::modeNoTruncate | CFile::modeWrite);
...

[nancy87]

Hi folks,
Sorry to interrupt,Can i post my question here as i had the same problem for
point 3 (use CStdioFile::WriteString to write these CStrings to the file ).
Do anyone have any example on it?


Thanks ,
nancy

[Elrond]

CString str = _T("String to write");
file.WriteString(str);

Note that WriteString does not add the end of line characters, so you would nee to do it yourself when you need it:

CString str = _T("String to write\r\n");
file.WriteString(str);

[nancy87]

Hi,

Thanks for ur prompt reply elrond,just want to ask ("String to write\r\n");--> what is this line for??

[Elrond]

An example for the end of line characters "\r\n"

If you don't use them, when you open the file with a text editor, everything will be on the same line. If that suits you, that's fine not to use them. But when writing a text file, in most cases the text will be on multiple lines/paragraphs, so you will need to be able to indicate the end of line and beginning of a new line. It is what these characters are for.