How to write buffer's value into .csv file?

Tyler_QQ

Hi all,

I have the buffer and wanted to write the buffer's value in the .csv file.

Here is my code：

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QWidget>
#include <QProcess>
#include <QThread>
#include <QList>
#include <QStringList>
#include <QDir>
#include <QDebug>
#include <QString>
#include <QFileDialog>
#include <QMessageBox>
#include <QFile>
#include <stdio.h>
#include "unistd.h"

.......

QString filename = "/home/tyler/test2/Qtdata.csv";
QFile file( filename );
if( file.open(QFile::ReadWrite)){
   QTextStream out(&filename);
   for(int i = 0; i < datanum; i++){
         QString tmp = QString("%1,%2,%3\n").arg(b_data[0][i]).arg(b_data[1][i]).arg(b_data[2][i]);
         out << tmp;
           }              
  }
  file.close();

The Qtdata.csv always get nothing .

Could anyone give me some advice.

Thank you!

Best regards,

Tyler_QQ

mrjj

Hi
Do you get absolutely
nothing in the file or just ~~black~~ blank lines?

You should check the value of datanum
qDebug() << "lines:" << datanum;

jsulm

@Tyler_QQ said in How to write buffer's value in to .csv file?:

QTextStream out(&filename);

should be

QTextStream out(&file);

You're writing into the string containing the file name!

Tyler_QQ

@mrjj

Hi mrjj,

Thanks for your reply.

There is just blank line in my .csv file.

The value of datanum and tmp's three value are correct.

Again thanks for your advice.

Best Regards,

Tyler_QQ

mrjj

And @jsulm sharp eye caught the real bug.
You are giving it the filename and not file :)
file and not filename should be used as he mentions.
So you write nothing to the file but all to your string :)

QTextStream out(&file~~name~~);

Tyler_QQ

@jsulm

Hi jsulm,

Thanks a lot!!

Through your advice, I had fixed this error.

Best Regards,

Tyler_QQ

mrjj

@Tyler_QQ
Super. Please mark as solved.