QWebSocket Hello World 示例

Question

我正在嘗試在項目中使用 QWebSockets。 我寫了一個小的“Hello World”示例來測試它是如何工作的。 問題：我可以啟動 WebSocket 服務器，但客戶端無法連接到它。 我的客戶端進入 QAbstractSocket::ConnectingState 但從未真正連接。

#if !defined(RAVI_SERVER_WEBSOCKETCLIENT_HPP)
#define RAVI_SERVER_WEBSOCKETCLIENT_HPP

//Qt includes
    //WebSocket
    #include <QtWebSockets/QWebSocketServer>
    #include <QtWebSockets/QWebSocket>
    //Util
    #include <QObject>
    #include <QDebug>

namespace ravi{
    namespace server{
        class WebSocketClient : public QObject{
            public:
                WebSocketClient(const QUrl &url, QObject* parent = nullptr);
            private slots:
                void handle_new_connection();
                void handle_close_connection();
                void handle_new_text_message();
                void handle_ssl_errors(const QList<QSslError> &errors);
                QWebSocket _socket;
        };
    }
}

#endif // RAVI_SERVER_WEBSOCKETCLIENT_HPP

#include "WebSocketClient.hpp"

ravi::server::WebSocketClient::WebSocketClient(const QUrl &url, QObject* parent):
QObject(parent),
_socket(){
    connect(&_socket, QOverload<QAbstractSocket::SocketError>::of(&QWebSocket::error),
    [=](QAbstractSocket::SocketError error){
        qDebug() << "Error";
    });
    connect(&_socket, &QWebSocket::connected, this, &WebSocketClient::handle_new_connection);
    connect(&_socket, &QWebSocket::disconnected, this, &WebSocketClient::handle_close_connection);
    connect(&_socket, QOverload<const QList<QSslError>&>::of(&QWebSocket::sslErrors),
            this, &WebSocketClient::handle_ssl_errors);
    qDebug() << url.path();
    qDebug() << url.port();
    qDebug() << url.url();
    qDebug() << url.host();
    _socket.open(url);
    qDebug() << _socket.state();
}


void ravi::server::WebSocketClient::handle_new_connection(){
    qDebug() << "New Connection";

    _socket.sendTextMessage(QStringLiteral("Hello, world!"));
    connect(&_socket, &QWebSocket::textMessageReceived,
            this, &WebSocketClient::handle_new_text_message);
}

void ravi::server::WebSocketClient::handle_close_connection(){
    qDebug() << "Closed Connection";
}

void ravi::server::WebSocketClient::handle_new_text_message(){
    qDebug() << "New Text Message";
}

void ravi::server::WebSocketClient::handle_ssl_errors(const QList<QSslError> &errors){
    Q_UNUSED(errors);
    qDebug() << "SSL";
    _socket.ignoreSslErrors();
}

#include "source/server/WebSocketClient.hpp"
#include <iostream>
int main(int argc, char const *argv[])
{
    ravi::server::WebSocketClient(QUrl("ws://127.0.0.1:8888"));
    std::string line;
    std::getline(std::cin, line);

}

#if !defined(RAVI_SERVER_WEBSOCKETSERVER_HPP)
#define RAVI_SERVER_WEBSOCKETSERVER_HPP

//Qt includes
//WebSocket
#include <QtWebSockets/QWebSocketServer>
#include <QtWebSockets/QWebSocket>
//Util
#include <QObject>
#include <QDebug>

namespace ravi{
    namespace server{
        class WebSocketServer : public QObject{
            Q_OBJECT
            public:
                WebSocketServer(int port, QObject* parent = nullptr);
            private:
                void handle_new_connection();
                void handle_close_connection();
                void handle_text_message();
                void handle_binary_message();
                void handle_disconnect();

                QWebSocketServer* _ws_server;
                std::vector<QWebSocket*> _clients;
        };
    }
}

#endif // RAVI_SERVER_WEBSOCKETSERVER_HPP

#include "WebSocketServer.hpp"

ravi::server::WebSocketServer::WebSocketServer(int port, QObject* parent):
    QObject(parent),
    _ws_server(new QWebSocketServer("WebSocket Server", QWebSocketServer::NonSecureMode, this)){
    if(_ws_server->listen(QHostAddress::Any, port)){
        qDebug() << "Connect handlers";
        connect(_ws_server, &QWebSocketServer::newConnection, this, &WebSocketServer::handle_new_connection);
        connect(_ws_server, &QWebSocketServer::closed, this, &WebSocketServer::handle_close_connection);
    }
    if(_ws_server->isListening()){
        qDebug() << "Still Listening";
    }
}


void ravi::server::WebSocketServer::handle_new_connection(){
    qDebug() << "New Connection";
    QWebSocket *client = _ws_server->nextPendingConnection();

    connect(client, &QWebSocket::textMessageReceived, this, &WebSocketServer::handle_text_message);
    connect(client, &QWebSocket::binaryMessageReceived, this, &WebSocketServer::handle_binary_message);
    connect(client, &QWebSocket::disconnected, this, &WebSocketServer::handle_disconnect);

    _clients.push_back(client);
}

void ravi::server::WebSocketServer::handle_close_connection(){
    qDebug() << "Closed Connection";
}

void ravi::server::WebSocketServer::handle_text_message(){

}

void ravi::server::WebSocketServer::handle_binary_message(){

}

void ravi::server::WebSocketServer::handle_disconnect(){

}

#include "source/server/WebSocketServer.hpp"
#include <iostream>

int main(int argc, char const *argv[])
{
    auto ws_server = ravi::server::WebSocketServer(8888);

    std::string line;
    std::getline(std::cin, line);


    return 0;
}

我看不出我做錯了什么。 從我的角度來看，這應該可行（絕地是邪惡的）。 希望任何幫助或條目鏈接已經涵蓋，我找不到任何。

Answer 1

你有2個錯誤：

• 通過不將客戶端對象分配給變量，它會立即被銷毀。
• Qt 需要一個事件循環來使信號、事件等工作，在這種情況下，一個 QCoreApplication 就足夠了。

#include "source/server/WebSocketClient.hpp"

#include <QCoreApplication>

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
    ravi::server::WebSocketClient client(QUrl("ws://127.0.0.1:8888"));
    return a.exec();
}

#include "source/server/WebSocketServer.hpp"

#include <QCoreApplication>

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
    ravi::server::WebSocketServer server(8888);
    return a.exec();
}

另一方面，我覺得很奇怪auto ws_server = ravi::server::WebSocketServer(8888); 不會產生編譯錯誤，因為作為 WebSocketServer，QObject 不應允許復制構造函數。