前言
html5支持使用websocket协议与服务器保持一个长连接，方便双方互相传输数据，而且服务器也能主动发送信息给客户端，而在这之前使用HTTP是很难做到的。下面介绍使用C++实现的websocket++的简单使用。websocket++更详细介绍点此。
websocket++需要boost的支持，所以工程中需要包含boost的头文件和库。boost在VS中的如何使用参考此文章。
C++代码
1 #include "stdafx.h" 2 #include <iostream> 3 4 using namespace std; 5 6 #include <websocketpp/config/asio_no_tls.hpp> 7 #include <websocketpp/server.hpp> 8 9 typedef websocketpp::server<websocketpp::config::asio> WebsocketServer; 10 typedef WebsocketServer::message_ptr message_ptr; 11 12 using websocketpp::lib::placeholders::_1; 13 using websocketpp::lib::placeholders::_2; 14 using websocketpp::lib::bind; 15 16 void OnOpen(WebsocketServer *server, websocketpp::connection_hdl hdl) 17 { 18 cout << "have client connected" << endl; 19 } 20 21 void OnClose(WebsocketServer *server, websocketpp::connection_hdl hdl) 22 { 23 cout << "have client disconnected" << endl; 24 } 25 26 void OnMessage(WebsocketServer *server, websocketpp::connection_hdl hdl, message_ptr msg) 27 { 28 string strMsg = msg->get_payload(); 29 cout << strMsg << endl; 30 31 string strRespon = "receive: "; 32 strRespon.append(strMsg); 33 34 server->send(hdl, strRespon, websocketpp::frame::opcode::text); 35 } 36 37 int main() 38 { 39 WebsocketServer server; 40 41 // Set logging settings 42 server.set_access_channels(websocketpp::log::alevel::all); 43 server.clear_access_channels(websocketpp::log::alevel::frame_payload); 44 45 // Initialize ASIO 46 server.init_asio(); 47 48 // Register our open handler 49 server.set_open_handler(bind(&OnOpen, &server, ::_1)); 50 51 // Register our close handler 52 server.set_close_handler(bind(&OnClose, &server, _1)); 53 54 // Register our message handler 55 server.set_message_handler(bind(&OnMessage, &server, _1, _2)); 56 57 //Listen on port 2152 58 server.listen(8090); 59 60 //Start the server accept loop 61 server.start_accept(); 62 63 //Start the ASIO io_service run loop 64 server.run(); 65 66 return 0; 67 }
Html代码
1 <!DOCTYPE html> 2 <html> 3 <head> 4 <title>Testing websockets</title> 5 </head> 6 <body> 7 <div> 8 <input type="submit" value="Start" onclick="start()" /> 9 </div> 10 <div id="messages"></div> 11 <script type="text/javascript"> 12 var webSocket = 13 new WebSocket('ws://localhost:8090'); 14 15 webSocket.onerror = function(event) { 16 onError(event) 17 }; 18 19 webSocket.onopen = function(event) { 20 onOpen(event) 21 }; 22 23 webSocket.onclose = function(event) { 24 onClose(event) 25 }; 26 27 webSocket.onmessage = function(event) { 28 onMessage(event) 29 }; 30 31 function onMessage(event) { 32 document.getElementById('messages').innerHTML 33 += '<br />' + event.data; 34 } 35 36 function onOpen(event) { 37 document.getElementById('messages').innerHTML 38 = 'Connection established'; 39 } 40 41 function onClose(event) { 42 document.getElementById('messages').innerHTML 43 += '<br />disconnection'; 44 } 45 function onError(event) { 46 alert(event.data); 47 } 48 49 function start() { 50 webSocket.send('hello'); 51 return false; 52 } 53 </script> 54 </body> 55 </html>
运行结果
