Qt5 拖拽

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QTextEdit>
#include <QUrl>

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

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

    bool ReadFile(QString strPath);

protected:
    void dragEnterEvent(QDragEnterEvent *event);
    void dropEvent(QDropEvent *event);


private:
    Ui::MainWindow *ui;

    QTextEdit *m_cTextEdit = NULL;
};

#endif // MAINWINDOW_H

#include "mainwindow.h"
#include "ui_mainwindow.h"

#include <QDragEnterEvent>
#include <QMimeData>
#include <QDebug>
#include <QList>
#include <QByteArray>
#include <QTextStream>

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

    m_cTextEdit = new QTextEdit(this);
    setCentralWidget(m_cTextEdit);
    m_cTextEdit->setAcceptDrops(false);
    this->setAcceptDrops(true);
}

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


void MainWindow::dragEnterEvent(QDragEnterEvent *event)
{
    if(event->mimeData()->hasFormat("text/uri-list"))
        //拖拽时间已经接受了用户的拖拽动作
        //if not the code,then dropEvent would not be called
        event->acceptProposedAction();
}

void MainWindow::dropEvent(QDropEvent *event)
{
    qDebug() << "dropEvent";
    QList<QUrl> urls = event->mimeData()->urls();
    if(urls.isEmpty())
        return;
    QString fileName = urls.first().toLocalFile();
    if(fileName.isEmpty())
        return;
    qDebug() << tr("%1  -- %2").arg(fileName).arg(fileName);

    if(ReadFile(fileName))
        setWindowTitle(tr("%1 -- %2").arg(fileName).arg("Drag File"));


}

bool MainWindow::ReadFile(QString strPath)
{
    if(strPath.isEmpty())
        return false;
    QFile file(strPath);
    if (!file.open(QIODevice::ReadOnly | QIODevice::Text))
            return false;
   // QByteArray text = file.readAll();//这样使用会产生中文乱码，应该使用下面的方式
    QTextStream in(&file);//想要读写文件不出现乱码尽量使用这种方式
    m_cTextEdit->setText(in.readAll());
    in.flush();
    file.close();

    return true;
}