qtscoket因为线程占用不能立即发送消息怎么解决-QT开发中文网

在Qt中，一个线程只能在事件循环（event loop）中处理事件，如果你的线程正在忙于某些计算或操作，并没有时间来处理socket通信的相关事件，那么你可以考虑使用Qt的多线程框架。

具体而言，你可以将socket通信放到一个单独的线程中，并通过该线程发送和接收消息。这样做的好处是，在socket通信期间，主线程不会被阻塞，用户界面仍然可以响应用户输入和操作。

下面是一份示例代码：

// SocketThread.h
#ifndef SOCKETTHREAD_H
#define SOCKETTHREAD_H

#include <QObject>
#include <QTcpSocket>

class SocketThread : public QObject
{
    Q_OBJECT
public:
    explicit SocketThread(QObject *parent = nullptr);
    ~SocketThread();

signals:
    void connected();
    void disconnected();
    void error(QString err);
    void messageReceived(QByteArray msg);

public slots:
    void connectToHost(QString host, int port);
    void disconnectFromHost();
    void sendMessage(QByteArray msg);

private slots:
    void onConnected();
    void onDisconnected();
    void onError(QAbstractSocket::SocketError error);
    void onReadyRead();

private:
     QTcpSocket *m_socket;
};

#endif // SOCKETTHREAD_H


// SocketThread.cpp
#include "SocketThread.h"

SocketThread::SocketThread(QObject *parent) : QObject(parent)
{
}

SocketThread::~SocketThread()
{
}

void SocketThread::connectToHost(QString host, int port)
{
   m_socket = new QTcpSocket(this);
   connect(m_socket, SIGNAL(connected()), this, SLOT(onConnected()));
   connect(m_socket, SIGNAL(disconnected()), this, SLOT(onDisconnected()));
   connect(m_socket, SIGNAL(error(QAbstractSocket::SocketError)), this, SLOT(onError(QAbstractSocket::SocketError)));
   connect(m_socket, SIGNAL(readyRead()), this, SLOT(onReadyRead()));

   m_socket->connectToHost(host, port);
}

void SocketThread::disconnectFromHost()
{
    if (m_socket) {
        m_socket->disconnectFromHost();
    }
}

void SocketThread::sendMessage(QByteArray msg)
{
    if (m_socket && m_socket->state() == QAbstractSocket::ConnectedState) {
        m_socket->write(msg);
    }
}

void SocketThread::onConnected()
{
    emit connected();
}

void SocketThread::onDisconnected()
{
    emit disconnected();
}

void SocketThread::onError(QAbstractSocket::SocketError error)
{
    QString err = "socket error: " + m_socket->errorString();
    emit error(err);
}

void SocketThread::onReadyRead()
{
    QByteArray data = m_socket->readAll();
    emit messageReceived(data);
}

在主线程中创建 QThread 对象，并将 SocketThread 对象移动到该线程中。然后，通过调用 QThread 的 start() 函数来启动线程。如下所示：

// main.cpp
#include <QCoreApplication>
#include <QThread>
#include "SocketThread.h"

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    // 创建线程对象
    QThread thread;

    // 创建 socket 线程对象并将其移动到新的线程中
    SocketThread* socket_thread = new SocketThread();
    socket_thread->moveToThread(&thread);

    // 连接信号和槽
    QObject::connect(&thread, &QThread::started, socket_thread, &SocketThread::connectToHost);
    QObject::connect(socket_thread, &SocketThread::disconnected, &thread, &QThread::quit);
    QObject::connect(socket_thread, &SocketThread::disconnected, socket_thread, &SocketThread::deleteLater);

    // 启动线程
    thread.start();

    return a.exec();
}

需要注意的是，由于 QTcpSocket 不是线程安全的，因此在跨线程使用时需要特别小心。在本例中，将 QTcpSocket 对象和相关的信号/槽都封装到了一个单独的类中，并确保它只在新线程中运行。这样可以避免跨线程访问问题。

希望以上信息对你有所帮助。