QTextStream讀寫文件

#include "widget.h"
#include "ui_widget.h"
#include<QTextStream>
#include<QFile>
#include<QDebug>
#include<QFileDialog>
#include<QPushButton>
//
#define cout qDebug() << "[" << __FILE__ << ":" << __LINE__ << "]"//打印的文件和行號,"__" not "_"

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

    writeData();
    readData();
}

Widget::~Widget()
{
    delete ui;
}

void Widget::writeData()
{
    QFile file;

    file.setFileName("../demo.txt");
    bool isOk = file.open(QIODevice::WriteOnly);
    if(true == isOk)
    {
       QTextStream stream(&file);

       //指定編碼
       stream.setCodec("UTF-8");
       stream << QString("狗先生") << 250;

       file.close();
    }
}

void Widget::readData()
{
    QFile file;

    file.setFileName("../demo.txt");
    bool isOk = file.open(QIODevice::ReadOnly);
    if(true == isOk)
    {
        QTextStream stream(&file);

        //指定編碼
        stream.setCodec("UTF-8");

        QString str;
        int a;
        stream >> str >> a;

        cout << str.toUtf8().data() << a;
        file.close();

    }
}

void Widget::on_pushButton_clicked()
{
    QString path = QFileDialog::getOpenFileName(this,
                                                "open","../");
    if(false == path.isEmpty())
    {
        QFile file;

        file.setFileName(path);
        bool isOk = file.open(QIODevice::ReadOnly);
        if(true == isOk)
        {
            QTextStream stream(&file);

            //指定編碼
            stream.setCodec("UTF-8");

           QString str = stream.readAll();
           ui->textEdit->setText(str);
       }
  }

}