QUdpSocket readReady 不发射信号

Question

我刚刚开始为我的 Qt 应用程序实现 UDP 客户端。我关注了this example。我能够向远程主机发送数据和从远程主机接收数据。这已经在我的远程主机以及我正在为其开发此应用程序的本地客户端上进行了验证（通过从我的 main.cpp 调用 handleReadyRead() 在本地进行验证）。我似乎无法让 QUdpSocket 发出它的 readyRead 信号。这是为什么？

main.cpp

#include <QGuiApplication>
#include <QQmlApplicationEngine>
#include <QTimer>
#include "udpclient.h"


static double value = 0;
static bool flash = true;
static UDPClient client;



   
int update1000()
{
    QByteArray Data;
    Data.append((char) 0x00);
    Data.append((char) 0x2c);
    Data.append((char) 0x1a);
    Data.append((char) 0x2c);
    Data.append((char) 0x92);
    Data.append((char) 0xe6);
    Data.append((char) 0xf6);
    Data.append((char) 0xa0);
    client.SendPacket(Data);

    return 0;
}

int packetReady()
{
    qInfo() << "packetReady";
    return 0;
}



int main(int argc, char *argv[])
{
    QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
    QGuiApplication app(argc, argv);

    qmlRegisterType<HorizontalBarGraph>("com.kubie.horizontalBarGraph", 1, 0, "HorizontalBarGraph");

    QQmlApplicationEngine engine;
    engine.load(QUrl(QStringLiteral("qrc:/main.qml")));
    if (engine.rootObjects().isEmpty())
        return -1;

    


    QObject *object = engine.rootObjects()[0];
   

    

    //qInfo() << "Initializing timer.";    
    QTimer timer1000;
    QObject::connect(&timer1000, &QTimer::timeout, update1000);
    timer1000.start(1000);



    return app.exec();
}

udpclient.h

#ifndef UDPCLIENT_H
#define UDPCLIENT_H


#include <QUdpSocket>

class UDPClient : public QObject
{
  Q_OBJECT

  public:
      explicit UDPClient(QObject *parent = nullptr);

      void SendPacket(const QByteArray &buffer);


  private:
      QUdpSocket *socket = nullptr;

  signals:

  public slots:
      void handleReadyRead();

};

#endif // UDPCLIENT_H

udpclient.cpp

#include "udpclient.h"

UDPClient::UDPClient(QObject *parent) :
    QObject(parent)
{
  socket = new QUdpSocket(this);

  //We need to bind the UDP socket to an address and a port
  //socket->bind(QHostAddress::LocalHost,1234);         //ex. Address localhost, port 1234
  socket->bind(QHostAddress::AnyIPv4,6969);         //ex. Address localhost, port 1234

  //connect(socket,SIGNAL(readyRead()),this,SLOT(handleReadyRead()));
  connect(socket, &QUdpSocket::readyRead, this, &UDPClient::handleReadyRead);

}


void UDPClient::SendPacket(const QByteArray &buffer)
{
    socket->writeDatagram(buffer, QHostAddress("192.168.174.10"), 6969);
}


void UDPClient::handleReadyRead()     //Read something
{
    qInfo() << socket->hasPendingDatagrams();

  QByteArray Buffer;
  Buffer.resize(socket->pendingDatagramSize());

  QHostAddress sender;
  quint16 senderPort;
  socket->readDatagram(Buffer.data(),Buffer.size(),&sender,&senderPort);
  qInfo() << Buffer;

  //The address will be sender.toString()
}

Answer 1

一个 QML 应用程序需要（至少）一个 QGuiApplication 到运行。您将在命令行或 IDE 调试应用程序输出 window 中获得关于此的调试输出。要针对此类问题获得更严重的警告，您可以设置环境变量 QT_FATAL_WARNINGS（有关详细信息，请参阅 QDebug documentation）

QUdpSocket readReady 不发射信号

QUdpSocket readReady not emitting signal

qt

qudpsocket