关于QUdpSocket和Qwt动态曲线的小例子

        最近项目中遇到的一个需求是关于用udp接收数据来显示一个动态曲线，觉得以后可能还会遇到于是写一个小例子记录一下。废话不多说直接贴代码。

        首先是数据发送端：

新建一个Qt Widgets Application，选择Qwidget，其中工程文件如下：

其中主要是QudpSocket的使用其他没什么可说的。

#-------------------------------------------------

#

# Project created by QtCreator 2018-06-07T19:21:13

#

#-------------------------------------------------

QT       += core gui network

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = QUdpServer

TEMPLATE = app

SOURCES += main.cpp\

        widgetserver.cpp

HEADERS  += widgetserver.h \

#    thetestdata.h

FORMS    += widgetserver.ui

头文件如下：

#ifndef WIDGETSERVER_H

#define WIDGETSERVER_H

#include 

#include 

#include 

namespace Ui {

class WidgetServer;

}

class WidgetServer : public QWidget

{

    Q_OBJECT

public:

    explicit WidgetServer(QWidget *parent = 0);

    ~WidgetServer();

private slots:

    void on_pushButton_send_clicked();

    void time_out_Slot();

private:

    void initSorket();

private:

    Ui::WidgetServer *ui;

    QUdpSocket* sender;

    QTimer*     timer;

};

#endif // WIDGETSERVER_H

源文件：

#include "widgetserver.h"

#include "ui_widgetserver.h"

#include "thetestdata.h"

#include 

#include 

#include 

WidgetServer::WidgetServer(QWidget *parent) :

    QWidget(parent),

    ui(new Ui::WidgetServer)

{

    ui->setupUi(this);

    timer = new QTimer(this);

    timer->start(1000);

    initSorket();

    connect(timer, SIGNAL(timeout()), this, SLOT(time_out_Slot()));

}

WidgetServer::~WidgetServer()

{

    delete ui;

}

//初始化QUdpSocket

void WidgetServer::initSorket()

{

    sender = new QUdpSocket(this);

    sender->bind(QHostAddress::Broadcast, 7755);

}

void WidgetServer::on_pushButton_send_clicked()

{

}

//时间槽函数 并对数据进行赋值发送

void WidgetServer::time_out_Slot()

{

    Massege_Data msg;

    int msg_length = sizeof(Massege_Data);

    qDebug()< 
  
    memset(&msg,0,sizeof(Massege_Data));
 
  
    msg.massege_header.massege_header = 1001;
 
  
    msg.massege_header.msg_num = 1;
 
  
    msg.test_data1 = 1;
 
  
    msg.test_data2 = 2;
 
  
    msg.massege_header.massege_length_uh = sizeof(Massege_Data);
 
  
 
  
    qsrand(QTime(0,0,0).secsTo(QTime::currentTime()));
 
  
    for(int i=0 ; i< 100;++i)
 
  
    {
 
  
        msg.the_y[i]= qrand()%90;
 
  
    }
 
  
 
  
    sender->writeDatagram((char*)&msg,sizeof(Massege_Data),QHostAddress::LocalHost,7755);
 
  
 
  
    //    qreal xy = sender->write((char*)&msg,sizeof(Massege_Data));
 
  
    //    if(xy==-1)
 
  
    //    {
 
  
    //        qDebug()<errorString();
 
  
    //    }
 
  
}
 
  
 
  
其中的结构体是单独的一个文件thetestdata.h放在和发送端的头文件和源文件相同的目录中：
 
  
 
  
#ifndef THETESTDATA_H
 
  
#define THETESTDATA_H
 
  
#pragma pack(1)
 
  
#ifndef _MASSEGE_HEADER
 
  
#define _MASSEGE_HEADER
 
  
typedef struct MassegeHeader{
 
  
    unsigned short int massege_header;//消息头
 
  
    unsigned short int massege_length_uh;//消息长度
 
  
    unsigned short int msg_num;//包数号
 
  
    unsigned short int msg_num_all;//总包数
 
  
    unsigned int       time_e;//时间戳
 
  
    unsigned char      spare_uc[9];//消息源
 
  
    unsigned char      bak[3];
 
  
 
  
}MassegeHeader;
 
  
#endif
 
  
 
  
#ifndef _MAGGEGE_DATA
 
  
#define _MAGGEGE_DATA
 
  
typedef struct Massege_Data{
 
  
    MassegeHeader         massege_header;
 
  
    unsigned short int    test_data1;
 
  
    unsigned short int    test_data2;
 
  
    unsigned short int    the_y[100];
 
  
}Massege_Data;
 
  
#endif
 
  
 
  
#pragma pack()
 
  
#endif // THETESTDATA_H
 
  
 
  
接下来是接收端也是新建Qt Widgets Application，选择Qwidget，要稍微复杂一点的就是重写了Qwt：
 
  
其界面如图：
 
  
 
  
其工程文件如下：
 
  
 
  
#-------------------------------------------------
 
  
#
 
  
# Project created by QtCreator 2018-06-09T20:57:32
 
  
#
 
  
#-------------------------------------------------
 
  
 
  
QT       += core gui network
 
  
 
  
CONFIG += qwt
 
  
DEFINES += QT_DLL QWT_DLL
 
  
 
  
LIBS += -L"D:\build-qwt-Desktop_Qt_5_6_3_MSVC2013_64bit-Debug\lib" -lqwtd
 
  
LIBS += -L"D:\build-qwt-Desktop_Qt_5_6_3_MSVC2013_64bit-Debug\lib" -lqwt
 
  
INCLUDEPATH += F:\Qt\Qt5.6.3\5.6.3\msvc2013_64\include\QWT
 
  
greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
 
  
 
  
TARGET = UdpClient
 
  
TEMPLATE = app
 
  
 
  
 
  
SOURCES += main.cpp\
 
  
        clientwidget.cpp
 
  
 
  
HEADERS  += clientwidget.h
 
  
 
  
FORMS    += clientwidget.ui
 
  
 
  
头文件如下：
 
  
 
  
#ifndef CLIENTWIDGET_H
 
  
#define CLIENTWIDGET_H
 
  
#include 
 
  
#include 
 
  
#include 
 
  
#include 
 
  
#include 
 
  
#include 
 
  
#include 
 
  
#include 
 
  
#include 
 
  
#include 
 
  
#include 
 
  
#include 
 
  
#include 
 
  
#include 
 
  
#include 
 
  
#include 
 
  
#include 
 
  
namespace Ui {
 
  
class ClientWidget;
 
  
}
 
  
 
  
class ClientWidget : public QWidget
 
  
{
 
  
    Q_OBJECT
 
  
 
  
public:
 
  
    explicit ClientWidget(QWidget *parent = 0);
 
  
    ~ClientWidget();
 
  
    //设置画布标题
 
  
    void setPlotTitle(const QString &strTitle);
 
  
    //重绘
 
  
    void reDraw();
 
  
    //设置x轴，y轴信息
 
  
    void setAxisTitles(QwtPlot::Axis asixId,const QString &strText);
 
  
    //设置x，y的值
 
  
    void setAxisRange(QwtPlot::Axis asixId,const double dStart,const double dEnd,const double dIndex=0.0);
 
  
    //创建网格
 
  
    QwtPlotGrid* createGrid();
 
  
    //获取网格
 
  
    QwtPlotGrid* getGrid();
 
  
    //设置是否显示
 
  
    void setGridIsShow(QwtPlot::Axis asixId,bool show);
 
  
    //设置网格类型和颜色
 
  
    void setGridColor(QColor color,qreal qrlinewidth,Qt::PenStyle ePenStyle);
 
  
    //创建曲线
 
  
    QwtPlotCurve* createCurve();
 
  
    //设置曲线是否显示
 
  
    void setCurveIsShow(QwtPlotCurve* pCurve,bool show);
 
  
    //删除曲线
 
  
    void delCurve(QwtPlotCurve* pCurve);
 
  
    //设置曲线数据和颜色
 
  
    void setCurveData(QwtPlotCurve* pCurve, QwtPointArrayData * const data,QPen pen);
 
  
 
  
    void addItem(int ixPos,int iYPos,const QwtText &qwtText);
 
  
    void delItem(QwtPlotItem *plotItem);
 
  
    void setItemPos(QwtPlotItem *plotItem,int ixPos,int iyPos);
 
  
    void setItemIsShow(QwtPlotItem *plotItem,bool show);
 
  
    void setTipMsg(QPoint pos,QString strText);
 
  
protected:
 
  
    void resizeEvent(QResizeEvent* re);
 
  
 
  
private slots:
 
  
    void on_pushButton_clicked();
 
  
    void readPendingDatagrams();
 
  
    void time_out_Slot();
 
  
private:
 
  
    Ui::ClientWidget *ui;
 
  
    QList<QwtPlotCurve*> m_listCurve;
 
  
    QList<QwtPlotItem*>  m_listItem;
 
  
    QwtPlotGrid *m_plotGrid;
 
  
    QwtPlot*     m_plot;
 
  
    QwtPlotPicker * m_picker;
 
  
    double  m_dXStart,m_dYStart,m_dXEnd,m_dYEnd;
 
  
    QUdpSocket* recvUdpSocket;
 
  
    QwtPlotCurve* testCurve;
 
  
    QwtPlotCurve* Msg_Udp_Curve;
 
  
    QTimer *timer;
 
  
};
 
  
 
  
#endif // CLIENTWIDGET_H
 
  
 
  
源文件如下：
 
  
 
  
#include "clientwidget.h"
 
  
#include "ui_clientwidget.h"
 
  
#include 
 
  
#include 
 
  
#include 
 
  
#include "thetestdata.h"
 
  
#include 
 
  
ClientWidget::ClientWidget(QWidget *parent) :
 
  
    QWidget(parent),
 
  
    ui(new Ui::ClientWidget)
 
  
{
 
  
    ui->setupUi(this);
 
  
    m_plot = NULL;
 
  
    m_plot = ui->plot;
 
  
    m_plotGrid = NULL;
 
  
    createGrid();
 
  
    m_listCurve.clear();
 
  
    m_listItem.clear();
 
  
    m_picker = new QwtPlotPicker(QwtPlot::xBottom,QwtPlot::yLeft,
 
  
                                  QwtPicker::PolygonRubberBand,
 
  
                                  QwtPicker::AlwaysOn,m_plot->canvas());
 
  
    m_picker->setRubberBandPen(QColor(Qt::green));
 
  
    m_picker->setRubberBand(QwtPicker::CrossRubberBand);
 
  
    m_picker->setTrackerPen(QColor(Qt::black));
 
  
    (void) new QwtPlotMagnifier(m_plot->canvas());
 
  
     (void) new QwtPlotPanner( m_plot->canvas() );
 
  
    recvUdpSocket = new QUdpSocket(this);
 
  
    recvUdpSocket->bind(QHostAddress::LocalHost, 7755);
 
  
 
  
    connect(recvUdpSocket, SIGNAL(readyRead()),
 
  
                  this, SLOT(readPendingDatagrams()));
 
  
    timer = new QTimer(this);
 
  
    timer->start(1000);
 
  
 
  
    //connect(timer, SIGNAL(timeout()), this, SLOT(time_out_Slot()));
 
  
    testCurve = NULL;
 
  
    testCurve = createCurve();
 
  
    Msg_Udp_Curve = NULL;
 
  
    Msg_Udp_Curve = createCurve();
 
  
 
  
}
 
  
 
  
ClientWidget::~ClientWidget()
 
  
{
 
  
    delete ui;
 
  
}
 
  
 
  
void ClientWidget::setPlotTitle(const QString &strTitle)
 
  
{
 
  
    QwtText qwtText = QwtText(strTitle);
 
  
    qwtText.setFont(QFont("Bitstream Charter",12,50,false));
 
  
    m_plot->setTitle(qwtText);
 
  
}
 
  
 
  
void ClientWidget::reDraw()
 
  
{
 
  
 
  
    m_plot->replot();
 
  
//    m_plot->detachItems();
 
  
}
 
  
 
  
void ClientWidget::setAxisTitles(QwtPlot::Axis asixId, const QString &strText)
 
  
{
 
  
    QwtText qwtText = QwtText(strText);
 
  
    qwtText.setFont(QFont("Bitstream Charter",9,50,false));
 
  
    m_plot->setAxisTitle(asixId,qwtText);
 
  
}
 
  
 
  
void ClientWidget::setAxisRange(QwtPlot::Axis asixId, const double dStart, const double dEnd, const double dIndex)
 
  
{
 
  
    m_plot->setAxisScale(asixId,dStart,dEnd,dIndex);
 
  
    if(asixId==QwtPlot::xBottom)
 
  
    {
 
  
        m_dXStart = dStart;
 
  
        m_dXEnd   = dEnd;
 
  
    }
 
  
    else if (asixId==QwtPlot::yLeft)
 
  
    {
 
  
        m_dYStart = dStart;
 
  
        m_dYEnd   = dEnd;
 
  
    }
 
  
}
 
  
 
  
QwtPlotGrid *ClientWidget::createGrid()
 
  
{
 
  
    if(m_plotGrid != NULL) return m_plotGrid;
 
  
    m_plotGrid = new QwtPlotGrid;
 
  
    setGridColor(Qt::gray,0.0,Qt::DotLine);
 
  
    m_plotGrid->attach(m_plot);
 
  
}
 
  
 
  
QwtPlotGrid *ClientWidget::getGrid()
 
  
{
 
  
    return m_plotGrid;
 
  
}
 
  
 
  
void ClientWidget::setGridIsShow(QwtPlot::Axis asixId, bool show)
 
  
{
 
  
    if(m_plotGrid == NULL) return;
 
  
    if(asixId == QwtPlot::xBottom)
 
  
        m_plotGrid->enableX(show);
 
  
    else if(asixId == QwtPlot::yLeft)
 
  
        m_plotGrid->enableY(show);
 
  
}
 
  
 
  
void ClientWidget::setGridColor(QColor color, qreal qrlinewidth, Qt::PenStyle ePenStyle)
 
  
{
 
  
    if(m_plotGrid == NULL) return;
 
  
    m_plotGrid->setPen(QPen(color,qrlinewidth,ePenStyle));
 
  
}
 
  
 
  
QwtPlotCurve *ClientWidget::createCurve()
 
  
{
 
  
    QwtPlotCurve* pCurve = new QwtPlotCurve();
 
  
    pCurve->setRenderHint(QwtPlotItem::RenderAntialiased);
 
  
    m_listCurve.append(pCurve);
 
  
    pCurve->attach(m_plot);
 
  
    return pCurve;
 
  
}
 
  
 
  
void ClientWidget::setCurveIsShow(QwtPlotCurve *pCurve, bool show)
 
  
{
 
  
    if(show)
 
  
    {
 
  
        if(!m_listCurve.contains(pCurve))
 
  
            m_listCurve.append(pCurve);
 
  
        pCurve->attach(m_plot);
 
  
    }
 
  
    else
 
  
    {
 
  
        pCurve->detach();
 
  
    }
 
  
}
 
  
 
  
void ClientWidget::delCurve(QwtPlotCurve *pCurve)
 
  
{
 
  
    if(m_listCurve.contains(pCurve)) return;
 
  
    m_listCurve.removeOne(pCurve);
 
  
    pCurve->detach();
 
  
    delete pCurve;
 
  
    pCurve = NULL;
 
  
}
 
  
 
  
void ClientWidget::setCurveData(QwtPlotCurve *pCurve,QwtPointArrayData * const data, QPen pen)
 
  
{
 
  
    if(pCurve != NULL)
 
  
        pCurve->setData(data);
 
  
    pCurve->setPen(pen);
 
  
}
 
  
 
  
void ClientWidget::addItem(int ixPos, int iYPos, const QwtText &qwtText)
 
  
{
 
  
 
  
}
 
  
 
  
void ClientWidget::delItem(QwtPlotItem *plotItem)
 
  
{
 
  
 
  
}
 
  
 
  
void ClientWidget::setItemPos(QwtPlotItem *plotItem, int ixPos, int iyPos)
 
  
{
 
  
 
  
}
 
  
 
  
void ClientWidget::setItemIsShow(QwtPlotItem *plotItem, bool show)
 
  
{
 
  
 
  
}
 
  
 
  
void ClientWidget::setTipMsg(QPoint pos, QString strText)
 
  
{
 
  
 
  
}
 
  
 
  
void ClientWidget::resizeEvent(QResizeEvent *re)
 
  
{
 
  
    int w = re->size().width();
 
  
    QWidget::resizeEvent(re);
 
  
}
 
  
 
  
void ClientWidget::on_pushButton_clicked()
 
  
{
 
  
    timer->stop();
 
  
}
 
  
 
  
void ClientWidget::readPendingDatagrams()
 
  
{
 
  
    Massege_Data msg;
 
  
    memset(&msg,0,sizeof(Massege_Data));
 
  
    while (recvUdpSocket->hasPendingDatagrams()) {
 
  
            QByteArray datagram;
 
  
            QHostAddress sender = QHostAddress::LocalHost;
 
  
            quint16 senderPort = 7755;
 
  
            datagram.resize(recvUdpSocket->pendingDatagramSize());
 
  
            recvUdpSocket->readDatagram((char*)&msg, sizeof(Massege_Data),
 
  
                                    &sender,&senderPort);
 
  
        }
 
  
 
  
        QVector<double> xs;
 
  
        QVector<double> ys;
 
  
        for (int i=0;i<100;++i)
 
  
        {
 
  
            ys.append(msg.the_y[i]);
 
  
            xs.append(i);
 
  
        }
 
  
        //构造曲线数据
 
  
        QwtPointArrayData * const data = new QwtPointArrayData(xs, ys);
 
  
//
 
  
 
  
        setAxisRange(QwtPlot::xBottom,0,100);
 
  
        setAxisRange(QwtPlot::yLeft,0,100);
 
  
        setAxisTitles(QwtPlot::xBottom,"x__");
 
  
        setAxisTitles(QwtPlot::yLeft,QString("y__"));
 
  
 
  
        setCurveData(Msg_Udp_Curve,data,QPen(Qt::blue));
 
  
        reDraw();
 
  
}
 
  
 
  
void ClientWidget::time_out_Slot()
 
  
{
 
  
    if(testCurve != NULL)
 
  
        delCurve(testCurve);
 
  
    Massege_Data msg_test;
 
  
    int msg_length = sizeof(Massege_Data);
 
  
    qDebug()< 
  
    memset(&msg_test,0,sizeof(Massege_Data));
 
  
    msg_test.massege_header.massege_header = 1001;
 
  
    msg_test.massege_header.msg_num = 1;
 
  
 
  
    qsrand(QTime(0,0,0).secsTo(QTime::currentTime()));
 
  
    for(int i=0 ; i< 100;++i)
 
  
    {
 
  
           msg_test.the_y[i] = qrand()%90;
 
  
    }
 
  
    QVector<double> xs;
 
  
    QVector<double> ys;
 
  
    for (int i=0;i<100;++i)
 
  
    {
 
  
        ys.append(msg_test.the_y[i]);
 
  
        xs.append(i);
 
  
    }
 
  
    //构造曲线数据
 
  
    QwtPointArrayData * const data = new QwtPointArrayData(xs, ys);
 
  
    setAxisRange(QwtPlot::xBottom,0,100);
 
  
    setAxisRange(QwtPlot::yLeft,0,100);
 
  
 
  
 
  
    setCurveData(testCurve,data,QPen(Qt::red));
 
  
    reDraw();
 
  
 
  
}
 
  
 
  
其中结构体文件和发送端一样也是放在与接收端的源文件一个目录。
 
  
其显示的效果如下: