基于asio实现一个websocket客户端

好的，以下是一个使用asio实现的websocket客户端的示例代码：

#include <iostream>
#include <asio.hpp>
#include <string>

using asio::ip::tcp;

class WebsocketClient {
public:
    WebsocketClient(asio::io_context& io_context, const std::string& server, const std::string& path)
        : m_resolver(io_context),
        m_socket(io_context),
        m_server(server),
        m_path(path) {
    }

    void Connect() {
        tcp::resolver::query query(m_server, "80");
        m_resolver.async_resolve(query, [this](const asio::error_code& error, tcp::resolver::iterator endpoint_iterator) {
            if (!error) {
                asio::async_connect(m_socket, endpoint_iterator, [this](const asio::error_code& error, tcp::endpoint) {
                    if (!error) {
                        // 发送HTTP请求
                        asio::streambuf request;
                        std::ostream request_stream(&request);
                        request_stream << "GET " << m_path << " HTTP/1.1\r\n";
                        request_stream << "Host: " << m_server << "\r\n";
                        request_stream << "Upgrade: websocket\r\n";
                        request_stream << "Connection: Upgrade\r\n";
                        request_stream << "Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==\r\n";
                        request_stream << "Sec-WebSocket-Version: 13\r\n\r\n";
                        asio::async_write(m_socket, request, [this](const asio::error_code& error, std::size_t) {
                            if (!error) {
                                // 读取HTTP响应
                                asio::async_read_until(m_socket, m_response, "\r\n\r\n", [this](const asio::error_code& error, std::size_t) {
                                    if (!error) {
                                        std::istream response_stream(&m_response);
                                        std::string http_version;
                                        response_stream >> http_version;
                                        unsigned int status_code;
                                        response_stream >> status_code;
                                        std::string status_message;
                                        std::getline(response_stream, status_message);
                                        if (http_version.substr(0, 5) == "HTTP/") {
                                            if (status_code == 101 && status_message == "Switching Protocols") {
                                                // 连接成功，开始读取websocket数据
                                                ReadWebsocketData();
                                            }
                                            else {
                                                std::cout << "连接失败: " << status_code << " " << status_message << std::endl;
                                            }
                                        }
                                        else {
                                            std::cout << "连接失败: 无效的HTTP响应" << std::endl;
                                        }
                                    }
                                    else {
                                        std::cout << "连接失败: " << error.message() << std::endl;
                                    }
                                });
                            }
                            else {
                                std::cout << "连接失败: " << error.message() << std::endl;
                            }
                        });
                    }
                    else {
                        std::cout << "连接失败: " << error.message() << std::endl;
                    }
                });
            }
            else {
                std::cout << "连接失败: " << error.message() << std::endl;
            }
        });
    }

    void SendWebsocketData(const std::string& data) {
        if (m_socket.is_open()) {
            asio::streambuf streambuf;
            std::ostream stream(&streambuf);
            stream << static_cast<char>(0x81); // FIN=1, Opcode=1(Text)
            stream << static_cast<char>(data.size()); // Payload Length
            stream.write(data.c_str(), data.size()); // Payload Data
            asio::async_write(m_socket, streambuf, [this](const asio::error_code& error, std::size_t) {
                if (error) {
                    std::cout << "发送数据失败: " << error.message() << std::endl;
                }
            });
        }
        else {
            std::cout << "连接已关闭" << std::endl;
        }
    }

private:
    void ReadWebsocketData() {
        asio::async_read(m_socket, asio::buffer(m_buffer), [this](const asio::error_code& error, std::size_t length) {
            if (!error) {
                // 解析websocket数据
                if (length >= 2) {
                    unsigned char fin = m_buffer[0] & 0x80;
                    unsigned char opcode = m_buffer[0] & 0x0F;
                    unsigned char mask = m_buffer[1] & 0x80;
                    unsigned char payload_length = m_buffer[1] & 0x7F;
                    if (opcode == 1 && mask == 1) {
                        if (payload_length <= 125) {
                            std::string payload_data;
                            for (std::size_t i = 0; i < payload_length; i++) {
                                payload_data += m_buffer[2 + i] ^ m_buffer[(i % 4) + 6];
                            }
                            std::cout << "接收到数据: " << payload_data << std::endl;
                        }
                        else {
                            std::cout << "接收到数据: 数据长度超过125" << std::endl;
                        }
                    }
                    else {
                        std::cout << "接收到数据: 不是文本消息" << std::endl;
                    }
                }
                // 继续读取websocket数据
                ReadWebsocketData();
            }
            else {
                std::cout << "连接已关闭" << std::endl;
            }
        });
    }

private:
    tcp::resolver m_resolver;
    tcp::socket m_socket;
    std::string m_server;
    std::string m_path;
    asio::streambuf m_response;
    std::array<char, 1024> m_buffer;
};

int main() {
    asio::io_context io_context;
    WebsocketClient client(io_context, "echo.websocket.org", "/v1/");
    client.Connect();
    while (true) {
        std::string message;
        std::cout << "请输入要发送的数据: ";
        std::getline(std::cin, message);
        if (!message.empty()) {
            client.SendWebsocketData(message);
        }
    }
    return 0;
}

该程序连接到 `echo.websocket.org` 服务器，并在控制台中等待用户输入websocket数据。它通过发送HTTP请求将连接升级到websocket，并在连接成功后开始读取websocket数据。它还提供了一个 `SendWebsocketData` 方法，以便用户可以在控制台中输入数据并发送到服务器。当程序接收到websocket数据时，它会解析数据并显示在控制台中。

注意：该示例程序仅用于演示如何使用asio实现websocket客户端。实际上，websocket协议比示例程序复杂得多，需要处理更多的细节和错误情况。如果要在生产环境中使用websocket客户端，请使用现有的websocket库，例如 `websocketpp` 或 `boost.beast`。