4.录屏软件录屏端和接收端程序

main.cpp
\

Sender.cpp

HEADERS
+=
\

Sender.h

QT
+=
network widgets

#ifndef SENDER_H

#define SENDER_H

#include <QObject>

#include <QUdpSocket>

class Sender : public QObject

{

    Q_OBJECT

public:

    explicit Sender(QObject *parent = 0);

    QUdpSocket* _socket;

    void sendFrame(const QByteArray& buf);

signals:

public slots:

    void slotSendOneFrame();

};

#endif // SENDER_H

#include "sender.h"

#include <QApplication>

#include <QScreen>

#include <QDesktopWidget>

#include <QPixmap>

#include <QBuffer>

#include <QHostAddress>

#include <QDateTime>

Sender::Sender(QObject *parent) :

    QObject(parent)

{

    _socket = new QUdpSocket;

}

void Sender::sendFrame(const QByteArray &buf)

{

    int blockSize = 1024;

    //获得块的大小

    int blockCount = buf.size() / blockSize +

            (buf.size() % blockSize > 0 ? 1 : 0);

    //qint64表示的是：typedef long long，currentMSecsSinceEpoch获得时间额毫秒值

    qint64 timestamp = QDateTime::currentMSecsSinceEpoch();

    for(int i = 0; i < blockCount; i++)

    {

        QByteArray block;

        //追加byte数组到byte数组中

        block.append((char*)&timestamp, sizeof(timestamp));

        block.append(char(blockCount));

        block.append(char(i + 1));

        block += buf.mid(i * blockSize,blockSize);

        //向指定地址的机器上发送数据，如果成功返回的是块的大小，如果不成功返回-1

        if(_socket->writeDatagram(block, block.size(),

               QHostAddress("127.0.0.1"), 10001) != block.size()){

            qDebug() <<"send error"<<i<<blockCount;

        }

        else

        {

            qDebug() << "send block "<< i << blockCount;

        }

    }

}

void Sender::slotSendOneFrame()

{

    //capture desktop

    QPixmap pixmap = QApplication::screens().at(0)->grabWindow(QApplication::desktop()->winId());

    //pixmap.save("../desktop.jpg");

    QBuffer memFile;

    //QBuffer.open()函数从QIODevice::open()函数重载实现

    memFile.open(QIODevice::ReadWrite);

    pixmap.save(&memFile,"JPG");

    memFile.close();

    QByteArray buf = memFile.buffer();

    //发送数据

    sendFrame(buf);

}

#include "sender.h"

#include <QApplication>

#include <QTimer>

int main(int argc,char* argv[])

{

    QApplication app(argc,argv);

    Sender* sender = new Sender;

    //这个静态方法调用在给定的时间之后调用信号

    QTimer::singleShot(1, sender, SLOT(slotSendOneFrame()));

    QTimer* timer = new QTimer;

    app.connect(timer, SIGNAL(timeout()), sender, SLOT(slotSendOneFrame()));

    timer->setInterval(1000 * 1800);

    //开启定时器

    timer->start();

    return app.exec();

}

main.cpp
\

Recver.cpp
\

MyWidget.cpp

HEADERS
+=
\

Recver.h
\

MyWidget.h

QT
+=
widgets gui
network

#ifndef RECVER_H

#define RECVER_H

#include <QObject>

#include <QUdpSocket>

class Recver : public QObject

{

    Q_OBJECT

public:

    explicit Recver(QObject *parent = 0);

    QUdpSocket* _socket;

    QList<QByteArray> _blocks;

    qint64 _timestamp;

signals:

    void sigFrameArrive(QByteArray ba);

public slots:

    void slotDataArrive();

};

#endif // RECVER_H

#include "Recver.h"

#include <QDebug>

Recver::Recver(QObject *parent) :

    QObject(parent)

{

    _socket = new QUdpSocket;

    //绑定端口

    _socket->bind(10001);

    //  _socket->setSocketOption();

    //Sets the given option to the value described by value.

    _socket->setSocketOption(QAbstractSocket::ReceiveBufferSizeSocketOption, 1024*1024*8);

    QVariant var = _socket->socketOption(QAbstractSocket::ReceiveBufferSizeSocketOption);

    qDebug() << "recv buffer is"<< var;

    connect(_socket, SIGNAL(readyRead()), this, SLOT(slotDataArrive()));

    _timestamp = 0;

}

void Recver::slotDataArrive()

{

    //如果至少一个数据包等待读取的时候，返回true，否则返回false

    while(_socket->hasPendingDatagrams())

    {

        int size = _socket->pendingDatagramSize();

        QByteArray buf(size,0);

        _socket->readDatagram(buf.data(),buf.size());

        qint64 timestamp = *(qint64*)buf.data();

        if(timestamp > _timestamp)

        {

            qDebug() << "timestamp > _timestamp";

            _timestamp = timestamp;

            _blocks.clear();

        }

        else if(timestamp < _timestamp)

        {

            qDebug() << "timestamp <  _timestamp";

            continue;

        }

        //emit this->sigFrameArrive(buf);

        _blocks.append(buf);

        int totalBlockCount = (uchar)_blocks.at(0).at(8);

        qDebug() << "recv block" << (int)totalBlockCount << (int)(uchar)buf[9];

        //qDebug() << totalBlockCount << _blocks.size();

        //如果块儿的大小 == 总块儿的数量

        if(_blocks.size() == totalBlockCount)

        {

             qDebug() << "recy frame";

             QByteArray frame;

             for(int i = 0; i < _blocks.size();i++)

             {

                 frame += _blocks.at(i).mid(10);

             }

             _blocks.clear();

             emit this->sigFrameArrive(frame);

        }

    }

}

#ifndef MYWIDGET_H

#define MYWIDGET_H

#include <QWidget>

class MyWidget : public QWidget

{

    Q_OBJECT

public:

    explicit MyWidget(QWidget *parent = 0);

    QByteArray _buf;

    void paintEvent(QPaintEvent *);

signals:

public slots:

    void slotFrameArrive(QByteArray);

};

#endif // MYWIDGET_H

#include "MyWidget.h"

#include <QPainter>

MyWidget::MyWidget(QWidget *parent) :

    QWidget(parent)

{

}

void MyWidget::slotFrameArrive(QByteArray ba)

{

    _buf = ba;

    update();

}

void MyWidget::paintEvent(QPaintEvent *)

{

    QPainter p(this);

    QPixmap pixmap;

    //加载数据从buf中

    pixmap.loadFromData(_buf, "JPG");

    //开始绘图

    p.drawPixmap(0, 0, pixmap);

}

#include <QApplication>

#include "MyWidget.h"

#include "recver.h"

int main(int argc,char* argv[])

{

    QApplication app(argc,argv);

    MyWidget w;

    w.show();

    Recver* recver = new Recver;

    app.connect(recver, SIGNAL(sigFrameArrive(QByteArray)),

                    &w, SLOT(slotFrameArrive(QByteArray)));

    return app.exec();

}