QT读写csv文件（文本文件）

//写数据

void MainWindow::on_pushButton_clicked()

{

    if(dataMap.size()<=0){

        QMessageBox::information(this,"","请先进行读数据操作！",NULL);

        return;

    }

    QFile file("C:/20171114.csv");

    QTextStream textStream;

    if(!file.open(QFile::WriteOnly | QFile::Truncate | QFile::Text)){

        QMessageBox::information(this,"","无生成盘符，应生成在C:/20171114.csv",NULL);

    }else{

        textStream.setDevice(&file);

        textStream.setCodec("GB2312");

        QMap<QString,int>dataNumMap;

        for(auto it = dataMap.begin();it != dataMap.end();++it){

            dataNumMap.insert(it.key(),it.value().size());

        }

        int maxNum = dataNumMap[dataNumMap.firstKey()];

        for(auto it = dataMap.begin();it != dataMap.end();++it){

            int temp = dataNumMap[it.key()];

            if(maxNum <= temp)

                maxNum = temp;

        }

        QString headerStr = "SevRNP,Number";

        for(int i=1;i<=maxNum;i++){

            headerStr = headerStr + ",TagRNP" + QString::number(i);

        }

        textStream << headerStr +"\n";

        //写数据

        QString dataStr;

        for(auto it = dataMap.begin();it != dataMap.end();++it){

            dataStr = it.key()+","+QString::number(it.value().size());

            for(int i=0;i 
  
                QStringList value = it.value();
 
  
                dataStr += ","+value.at(i);
 
  
            }
 
  
            textStream << dataStr +"\n";
 
  
            dataStr.clear();
 
  
        }
 
  
    }
 
  
    file.close();
 
  
    this->close();
 
  
    QMessageBox::information(this,"","文件生成在C:/20171114.csv",NULL);
 
  
}
 
  
 
  
//读取数据
 
  
 
  
void MainWindow::on_pushButton_2_clicked()
 
  
{
 
  
    QFile file("C:/20171113.csv");
 
  
    if(!file.open(QIODevice::ReadOnly | QIODevice::Text)){
 
  
        QMessageBox::information(this,"","文件放错位置，应放置C:/20171113.csv",NULL);
 
  
    }else{
 
  
        QTextStream textStream(&file);
 
  
        textStream.setCodec("GB2312");
 
  
        textStream.readLine();
 
  
        //读数据
 
  
        QStringList firstData = textStream.readLine().split(",");
 
  
        SevRNP = firstData.at(0);
 
  
        TagRNPList.append(firstData.at(1));
 
  
        while(!textStream.atEnd()){
 
  
            QStringList tempData = textStream.readLine().split(",");
 
  
            if(tempData.at(0) == SevRNP){
 
  
                TagRNPList.append(tempData.at(1));
 
  
                continue;
 
  
            }
 
  
            dataMap.insert(SevRNP,TagRNPList);
 
  
            SevRNP = tempData.at(0);
 
  
            TagRNPList.clear();
 
  
            TagRNPList.append(tempData.at(1));
 
  
        }
 
  
        QMessageBox::information(this,"","数据读取完成，请写数据生成文件！",NULL);
 
  
    }
 
  
    file.close();
 
  
//    QString len ;
 
  
//    for(auto it = dataMap.begin();it != dataMap.end();++it){
 
  
//        len += QString::number(it.value().size())+",";
 
  
//    }
 
  
}