c++ - 通过 Qt NamedPipe 发送数据时追加数据

Question

使用QT通过Namedpipe发送数据时出现数据追加问题

本地服务器.h

#ifndef LOCALSERVER_H
#define LOCALSERVER_H

#include "QLocalSocket"
#include "QLocalServer"

class QLocalSocket;

class LocalServer : public QLocalServer
{
    Q_OBJECT
public:
    explicit LocalServer(QObject *parent = 0);
    void send(QString &msj);
    QLocalSocket *mSocket;


private slots:
    void receive();

private:

};

#endif // LOCALSERVER_H

本地服务器.cpp

#include "localserver.h"
#include "QLocalSocket"
#include "QTextStream"
#include "QMessageBox"
LocalServer::LocalServer(QObject *parent) : QLocalServer(parent)
{
    mSocket = nullptr;
    connect(this,&LocalServer::newConnection,[&](){
        mSocket = nextPendingConnection();
    });
    qDebug()<<"Hello World";
}

void LocalServer::send(QString &msj)
{
    qDebug()<<"Sending Data";
    if(mSocket)
    {
        QTextStream T(mSocket);
        T<<msj.toStdString().c_str();
        mSocket->flush();
    }

}

void LocalServer::receive()
{
        qDebug()<<"Im here";
        QDataStream in(mSocket);
        in.setVersion(QDataStream::Qt_5_2);
        mSocket->readAll();
        qDebug()<<"Data Received";
}

小部件.h

#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>
#include "QProcess"
#include "QTimer"
#include "QLocalSocket"
#include "localserver.h"
namespace Ui {
class Widget;
}



class Widget : public QWidget
{
    Q_OBJECT

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

    void Connection();
private slots:
    void on_start_clicked();

    void on_send_clicked();

    void on_quit_clicked();


    void detect_connection();

    void connect_terminate();

    void connected();
    void send_data();
    void receive_data();


    QString RandomData();
    void on_pbtn_Stop_clicked();

private:
    Ui::Widget *ui;
    LocalServer *mLocalServer;
    QTimer *timer;
    QLocalSocket *mSocket;
    bool first;
    QString data_received;

};

#endif // WIDGET_H

小部件.cpp

#include "widget.h"
#include "ui_widget.h"
#include "QProcess"
#include "QDebug"
#include "localserver.h"
#include "QMessageBox"

#include <iostream>
#include <cstdlib>
#include <ctime>
using namespace std;

Widget::Widget(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Widget)
{
    ui->setupUi(this);
     Connection();
    first = true;
}
void Widget::Connection()
{
    mLocalServer = new LocalServer(this);
    mLocalServer->listen("Server1");
    connect(mLocalServer,SIGNAL(newConnection()),this,SLOT(detect_connection()));

    first = true;

    timer = new QTimer(this);
    timer->setInterval(8);
    connect(timer,SIGNAL(timeout()),this,SLOT(send_data()));

}

Widget::~Widget()
{

    delete ui;

}

void Widget::on_start_clicked()
{
    timer->start();

}

void Widget::on_send_clicked()
{
    timer->stop();
}

void Widget::on_quit_clicked()
{
    timer->stop();
    this->close();
}



void Widget::detect_connection()
{
    qDebug()<<"Write Pipe Established";
    mSocket = new QLocalSocket(this);
    mSocket->connectToServer("Server2");
    connect(mSocket,SIGNAL(disconnected()),this,SLOT(connect_terminate()));
    connect(mSocket,SIGNAL(connected()),this,SLOT(connected()));

        qDebug()<<"Connection Established, Ready to Read";
        connect(mSocket,&QLocalSocket::readyRead, [&]() {
            QTextStream T(mSocket);
            ui->receivedText->addItem(T.readAll());
        });
}

void Widget::connect_terminate()
{
    qDebug()<<"Read Server Connection Terminated";
    QString string = "Stop_Session";
    mLocalServer->send(string);
    ui->sentText->addItem(string);
}




void Widget::connected()
{
    qDebug()<<"Socket Connected to Server";
    QString s=" Connection Done ";
    mLocalServer->send(s);
}

void Widget::send_data()
{
    QString string = RandomData();
    mLocalServer->send(string);
    ui->sentText->addItem(string);
}
QString Widget::RandomData()
{
       srand(time(NULL));
       int random_number = rand()%(1920-0 + 1) + 0; // rand() return a number between ​0​ and RAND_MAX
       int random_number1 = rand()%(1080-0 + 1) + 0;
       int random_number2 = rand()%(10-0 + 1) + 0;
       QString s="Contour,"+QString::number(random_number)+","+QString::number(random_number1)+","+QString::number(random_number2);
// Basically this data in "s" gives the actual contours detected data but am using a random generator to test the Local Server and Socket .


return s;
}

void Widget::receive_data()
{
    QString string;
    QTextStream T(mSocket);
    T.readLine();
    if(T.readAll()=="Stop")
    {
        qDebug()<<"Socket About to Close";
        QString string = "Stop";
        mLocalServer->send(string);
    }
    else
    {
        qDebug()<<"Program can continue"<<T.readAll();
    }
}

void Widget::on_pbtn_Stop_clicked()
{
    timer->stop();
}

在接收端程序

接收器.cpp

void Receiver ::Declaration_Of_Server2()
{
    // Declaration Of LocalServer i.e Server2
    ServerIS = new LocalServer(this);
    ServerIS->listen("Server2");
    // Connect To a LocalSocket TO The Above LocalServer  i.e Server_IS with  Server_VS
    connect(ServerIS,SIGNAL(newConnection()),this,SLOT(DetectConnection_WithServer1()));
}

void CoFire_MainPage::DetectConnection_WithServer1()
{
    // Declaration of LocalSocket i.e Server_VS
    SocketIS = new QLocalSocket(this);
    SocketIS->connectToServer("Server1");
    connect(SocketIS,SIGNAL(readyRead()),this,SLOT(Receiving_VS_Data()));
}

void CoFire_MainPage::Receiving_VS_Data()
{
    // Receiving Vs Data From Socket "Socket_IS"
    QTextStream msg(SocketIS);
    QString str = msg.readLine();
    qDebug()<<" VS DATA : "<<str;
}

通过这个我试图将数据(例如:Contour,1000,800,1)从一个程序发送到另一个程序 速度为 1 个数据/8 毫秒，但在实际情况下，它甚至可能达到 1 毫秒的数据传输。 但是通过这个在接收端时不时地附加输入数据 (例如:Contour,1000,800,1Contour,200,400,1Contour,500,650,1 等...)。 但实际上预期的数据是 第一 轮廓,1000,800,1 下一个 轮廓,200,400,1 下一个 轮廓,500,650,1 等等……

这样，在我在接收方捕获和处理数据之前，数据就会被附加。 就这样失去了宝贵的情报。 我该如何解决这个问题。

Answer 1

readLine()等待行尾("\n" 或 "\r\n")，但在您的情况下您不发送它，您必须更改为以下内容:

QString Widget::RandomData(){
    srand(time(NULL));
    int random_number = rand()%(1920-0 + 1) + 0; // rand() return a number between ​0​ and RAND_MAX
    int random_number1 = rand()%(1080-0 + 1) + 0;
    int random_number2 = rand()%(10-0 + 1) + 0;
    return QString("Contour,%1,%2,%3\n")
            .arg(random_number)
            .arg(random_number1)
            .arg(random_number2);
}

---

另一方面，没有必要使用QString的引用，也没有必要使用toStdString().c_str()。

void LocalServer::send(const QString &msj)
{
    qDebug()<<"Sending Data";
    if(mSocket)
    {
        QTextStream T(mSocket);
        T << msj;
        mSocket->flush();
    }

}