void MainWindow::on_saveBtn_clicked()

{

    //本函数只是单独测试Qt保持为txt文本功能，与本串口程序无任何关系

    QDateTime da_time;

    QString time_str = da_time.currentDateTime().toString("yyyy-MM-dd HH-mm-ss");

//    QString runPath = QCoreApplication::applicationFilePath();

//    QString dirPath = QCoreApplication::applicationDirPath();

//    ui->pathview->setText(runPath); //X:qtworkspace/xxx/xx-desktop-debug/debug/xxx.exe

//    ui->pathview_2->setText(dirPath);//X:qtworkspace/xxx/xx-desktop-debug/debug/

    QDir *DataFile = new QDir;

    bool exist = DataFile->exists("DataFile");

    if(!exist)

    {

        bool isok = DataFile->mkdir("DataFile"); // 新建文件夹

            if(!isok)

                QMessageBox::warning(this,"sdf","can‘t mkdir",QMessageBox::Yes);

    }

    QString fileName = "DataFile/"+time_str+"datafile.txt";

    QString str = "this is testing for save data to txt file by Qt programming.";

    QFile file(fileName);

    if(!file.open(QIODevice::WriteOnly|QIODevice::Text|QIODevice::Append))

    {

        QMessageBox::warning(this,"sdf","can‘t open",QMessageBox::Yes);

    }

    QTextStream stream(&file);

    stream<<time_str+":"+str<<"\n";

    file.close();

}

代码比较简单，就不解释了。