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| 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" />
 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>
 
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