Qt

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QFile>
#include <QMessageBox>
#include <QTextStream>

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    QString filename = "1.txt";        //当前文件夹中
    QString str = "Qt QFile Test...";  //保存的文本内容
    QFile file(filename);
    if(!file.open(QIODevice::ReadWrite|QIODevice::Text))
    {
        QMessageBox::warning(this,"file write","can't open",QMessageBox::Yes);

    }
    QTextStream in(&file);
    in<<str<<"
";

}

MainWindow::~MainWindow()
{
      file.close();   // 关闭file
    delete ui;
}

在当前debug文件夹中会创建名为“1.txt”的文件