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!"<
     
      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!"<
     
      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("123");    quint32 n1(123);    txtOutput << QString::fromStdString(str_json) << endl;    txtOutput << n1 << endl;    f.close();