QWebSocket Hello World Example

Question

我正在尝试在项目中使用 QWebSockets。我写了一个小的"Hello World"示例来测试它是如何工作的。问题：我可以启动 WebSocket 服务器，但客户端无法连接到它。我的客户端进入QAbstractSocket：：ConnectingState，但从未真正连接过。

#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;
}

我看不出我做错了什么。从我的角度来看，这应该有效(绝地武士是邪恶的(。 希望有任何帮助或链接到已经涵盖的条目，我找不到任何帮助或链接。

Answer 1

您有 2 个错误：

• 如果不将客户端对象分配给变量，则立即将其销毁。
• Qt需要一个事件循环来使信号、事件等工作，在这种情况下，一个QCoreApplication就足够了。

#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，我觉得奇怪的是auto ws_server = ravi::server::WebSocketServer(8888);不会生成编译错误，因为作为 WebSocketServer QObject 不应该允许复制构造函数。