QT 读取txt文件的几种方法

废话不说直接上代码

１．

    QString displayString;

    QFile file("/home/alvin/text.txt");

    if(!file.open(QIODevice::ReadOnly | QIODevice::Text))

    {

        qDebug()<<"Can't open the file!"<<endl;

    }

    while(!file.atEnd())

    {

        QByteArray line = file.readLine();

        QString str(line);

        qDebug()<< str;

        displayString.append(str);

    }

       ui->textEdit->clear();

       ui->textEdit->setPlainText(displayString);

２．

    QString displayString;

    QFile file("/home/alvin/text.txt");

     if (!file.open(QIODevice::ReadOnly | QIODevice::Text))

         return;

     QTextStream in(&file);

     QString line = in.readLine();

     while (!line.isNull())

     {

//         process_line(line);

         line = in.readLine();

         displayString.append(line);

     }

       ui->textEdit->clear();

       ui->textEdit->setPlainText(displayString);

３．

     QString displayString;

     QFile file("/home/alvin/text.txt");

      if(!file.open(QIODevice::ReadWrite | QIODevice::Text)) {

          qDebug()<<"Can't open the file!"<<endl;

      }

      QTextStream stream(&file);

      QString line_in;

      stream.seek(file.size());//将当前读取文件指针移动到文件末尾

      int count = 0;

      while(count < 10)

      {

          stream << QObject::trUtf8("新建行:") <<++count<<"/n";

      }

      stream.seek(0);//将当前读取文件指针移动到文件开始

      while( !stream.atEnd())

      {

          line_in = stream.readLine();

          displayString.append(line_in);

          qDebug() << line_in;

      }

      ui->textEdit->clear();

      ui->textEdit->setPlainText(displayString);

以上是三种ＱＴ读取文件的方法，

源码在这里自行下载查看

https://pan.baidu.com/s/1pKIwzHL

Txt文件的写入的方法

    QFile f("./test.txt");

    if(!f.open(QIODevice::WriteOnly | QIODevice::Text))

    {

        cout << "Open failed." << endl;

        return data;

    }

    QTextStream txtOutput(&f);

    QString s1("");

    quint32 n1();

    txtOutput << QString::fromStdString(str_json) << endl;

    txtOutput << n1 << endl;

    f.close();