QFile文件读写

• 参考代码

  　　.h文件

#ifndef MYWIDGET_H
#define MYWIDGET_H

#include <QWidget>
#include <QFile>
#include <QFileDialog>
namespace Ui {
class myWidget;
}

class myWidget : public QWidget
{
    Q_OBJECT

public:
    explicit myWidget(QWidget *parent = 0);
    ~myWidget();

private slots:
    void on_read_clicked();

    void on_write_clicked();

private:
    Ui::myWidget *ui;
};

#endif // MYWIDGET_H

　　.cpp文件

#include "mywidget.h"
#include "ui_mywidget.h"

myWidget::myWidget(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::myWidget)
{
    ui->setupUi(this);
    setWindowTitle("QFile文件读写");
}

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

void myWidget::on_read_clicked()
{
QString path = QFileDialog::getOpenFileName(this,"open","../","TXT(*.txt)");
if(path.isEmpty()==false)
{
    QFile file(path);
    bool isOK = file.open(QIODevice::ReadOnly);
            if(isOK==true)
            {//方法1
//                QByteArray array = file.readAll();
//                ui->textEdit->setText(QByteArray(array));

                QByteArray array;//方法2
                while(file.atEnd()==false)
                {
                    array += file.readLine();
                }
                ui->textEdit->setText(array);
            }
            file.close();

}
}

void myWidget::on_write_clicked()
{
    QString path = QFileDialog::getSaveFileName(this,"save","../","TXT(*.txt)");
    if(path.isEmpty()==false)
    {
        QFile file;
        file.setFileName(path);
        bool isOK = file.open(QIODevice::WriteOnly);
        if(isOK==true)
        {
          QString str = ui->textEdit->toPlainText();
          //file.write(str.toUtf8());
          file.write(str.toStdString().data());
        }
        file.close();
    }

}