Save button MFC

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

To achieve your goal, try

Code:

---

#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
}

---

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.

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.

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

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

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 .

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

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

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

Code:

---

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

---

Another thing:

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

Code:

---

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

---

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

Code:

---

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:

Code:

---

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

---

Hi,

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

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.

Quote:

---

Originally Posted by Elrond

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

Code:

---

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

---

---

This code is not 100&#37; correct.
you should NOT add CR ('\r') character yourself, only LF ('\n'). CStdioFile::WriteString will then replace

Quote:

---

... any newline character ... written to the file as a carriage return–linefeed pair.

---

So, the correct code is:

Code:

---

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

---

Hi,

Do i still need mode create if i am just saving all the data into a file i already created.Also which is the line that opens up the directory so that u can save it to your file?Do i have to include seektoend() below
file.Open(filename, CFile::modeCreate | CFile::modeNoTruncate | CFile::modeWrite);


Thanks
nancy

Quote:

---

Originally Posted by nancy87

... Also which is the line that opens up the directory so that u can save it to your file?

---

You don't need to "open a directory".
Just use CFileDialog::GetPathName to obtain the full path name of a file and then pass this full path name to CStdIo::Open

Quote:

---

Originally Posted by nancy87

... Do i have to include seektoend() below
file.Open(filename, CFile::modeCreate | CFile::modeNoTruncate | CFile::modeWrite);

---

Yes, if you want to append new data to the old file.

hi guys
may i know which part i went wrong my code is here

void CabcdeDlg::OnBnClickedButton1()
{
CString strTextTime;
m_Time.GetWindowText(strTextTime);

CStdioFile File;

file.Open(lpszfilename, CFile::modeCreate | CFile::modeNoTruncate | CFile::modeWrite);
file.SeekToEnd();

file.Write(" hello world");

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

file.Close();

}

Do not forget to close file when writting string into a file.

Quote:

---

Originally Posted by kacaka

hi guys
may i know which part i went wrong my code is here
...

---

What is the problem?

Besides:

1. The variable filename is not defined.
2. You have to use CFileException to know whether your file operations succeded or not. See the code examples in MSDN articles CFile::Open and CStdioFile::CStdioFile

Hi,victorN
Understand that you do not want to spoonfeed me with giving me the code,but after trying quite long i still cant compile and my code shows lots of arrow care to rpovide more help??sorry i started this nt long ago.

Quote:

---

Originally Posted by kacaka

... after trying quite long i still cant compile and my code shows lots of arrow care to rpovide more help??

---

But you haven't shown your actual code yet! Nor showed you the exact compile errors!

So how could we help you more? :cool:

hi,
my code as above, may i ask why there are error c2228 like left of 'seekToEnd' must have class /struct union. the same error appears for 'write' n 'close','writestring',error c2065 lpszfileName undeclared identifier'writestring'.

The variable filename is not defined. ?? may i know hw to define tis.

for point 2
You have to use CFileException to know whether your file operations succeded or not. See the code examples in MSDN articles CFile::Open and CStdioFile::CStdioFile

CFileException Exception;
CFile File;

if(File.Open("c:\\data.txt", CFile::modeRead, &Exception) == FALSE)
{



may i know whether the code is correct .

Quote:

---

Originally Posted by kacaka

hi,
my code as above, may i ask why there are error c2228 like left of 'seekToEnd' must have class /struct union. the same error appears for 'write' n 'close','writestring',error c2065 lpszfileName undeclared identifier'writestring'.

The variable filename is not defined. ?? may i know hw to define tis.

for point 2
You have to use CFileException to know whether your file operations succeded or not. See the code examples in MSDN articles CFile::Open and CStdioFile::CStdioFile

CFileException Exception;
CFile File;

if(File.Open("c:\\data.txt", CFile::modeRead, &Exception) == FALSE)
{



may i know whether the code is correct .

---

You didn't show any of the code that generated those errors. Keep in mind though that C++ is case sensitive.

hi ,
i have solved the errors now and it works.any question i will post on a new thread thank you everyone