HTML5中怎么利用WebSocket实现实时视频文字传输

                      var wsServer = 'ws://localhost:9999/webSocket.ashx'; //基于.NET4.5服务器地址          //var wsServer = 'ws://localhost:1818'; //基于.NET服务器地址           var websocket = new WebSocket(wsServer); //创建WebSocket对象          //websocket.send("hello");//向服务器发送消息          //alert(websocket.readyState);//查看websocket当前状态          websocket.onopen = function (evt) {              //已经建立连接              alert("已经建立连接");          };          websocket.onclose = function (evt) {              //已经关闭连接              alert("已经关闭连接");          };          websocket.onmessage = function (evt) {              //收到服务器消息，使用evt.data提取              evt.stopPropagation()              evt.preventDefault()              //alert(evt.data);              writeToScreen(evt.data);              //websocket.close();          };          websocket.onerror = function (evt) {              //产生异常              //alert(evt.message);              writeToScreen(evt.message);          };          function sendMsg() {              if (websocket.readyState == websocket.OPEN) {                  msg = document.getElementById("msg").value;                  websocket.send(msg);                  writeToScreen("发送成功!");              } else {                  writeToScreen("连接失败!");              }          }           function writeToScreen(message) {              var pre = document.createElement("p");              pre.style.wordWrap = "break-word";              pre.innerHTML += message;              output.appendChild(pre);          }             
                  send     
     

readyState表示连接有四种状态：

CONNECTING (0)：表示还没建立连接；

OPEN (1)： 已经建立连接，可以进行通讯；

CLOSING (2)：通过关闭握手，正在关闭连接；

CLOSED (3)：连接已经关闭或无法打开；

url是代表 WebSocket 服务器的网络地址，协议通常是”ws”或“wss(加密通信)”,send 方法就是发送数据到服务器端；

close 方法就是关闭连接；

onopen连接建立，即握手成功触发的事件；

onmessage收到服务器消息时触发的事件；

onerror异常触发的事件；

onclose关闭连接触发的事件；

先说说基于.NET4.5的吧 ashx里面应该是这样写的

//得到当前WebSocket请求              HttpContext.Current.AcceptWebSocketRequest(async (context) =>              {                  WebSocket socket = context.WebSocket;//Socket                  while (true)                  {                      ArraySegment buffer = new ArraySegment(new byte[1024]);                      CancellationToken token;                      WebSocketReceiveResult result =                              await socket.ReceiveAsync(buffer, token);                      if (socket.State == WebSocketState.Open)                      {                          string userMessage = Encoding.UTF8.GetString(buffer.Array, 0,                                  result.Count);                          userMessage = "You sent: " + userMessage + " at " +                                  DateTime.Now.ToLongTimeString();                          buffer = new ArraySegment(Encoding.UTF8.GetBytes(userMessage));                          await socket.SendAsync(buffer, WebSocketMessageType.Text,                                  true, CancellationToken.None);                      }                      else { break; }                  }              });

然后需要注意的是 部署到IIS8上面  转到 Windows程序和功能 -打开Windows功能里面 IIS选项启动4.5 和WebSocket支持  否则会报错误的。

如果你不是Windows8 或者IIS的问题 你可以使用其他方式实现websocket服务器 比如.net socket模拟（因为websocket本身就是基于TCP的完全可以模拟只是规则特别..）

网上有人写了下面一段

class Program    {        static void Main(string[] args)        {            int port = 1818;            byte[] buffer = new byte[1024];             IPEndPoint localEP = new IPEndPoint(IPAddress.Any, port);            Socket listener = new Socket(localEP.Address.AddressFamily,SocketType.Stream, ProtocolType.Tcp);                        try{                listener.Bind(localEP);                listener.Listen(10);                 Console.WriteLine("等待客户端连接....");                Socket sc = listener.Accept();//接受一个连接                Console.WriteLine("接受到了客户端："+sc.RemoteEndPoint.ToString()+"连接....");                                //握手                int length = sc.Receive(buffer);//接受客户端握手信息                sc.Send(PackHandShakeData(GetSecKeyAccetp(buffer,length)));                Console.WriteLine("已经发送握手协议了....");                                //接受客户端数据                Console.WriteLine("等待客户端数据....");                length = sc.Receive(buffer);//接受客户端信息                string clientMsg=AnalyticData(buffer, length);                Console.WriteLine("接受到客户端数据：" + clientMsg);                 //发送数据                string sendMsg = "您好，" + clientMsg;                Console.WriteLine("发送数据：“"+sendMsg+"” 至客户端....");                sc.Send(PackData(sendMsg));                                Console.WriteLine("演示Over!");             }            catch (Exception e)            {                Console.WriteLine(e.ToString());            }        }         /// 
        /// 打包握手信息        /// 
        /// Sec-WebSocket-Accept        /// 数据包        private static byte[] PackHandShakeData(string secKeyAccept)        {            var responseBuilder = new StringBuilder();            responseBuilder.Append("HTTP/1.1 101 Switching Protocols" + Environment.NewLine);            responseBuilder.Append("Upgrade: websocket" + Environment.NewLine);            responseBuilder.Append("Connection: Upgrade" + Environment.NewLine);            responseBuilder.Append("Sec-WebSocket-Accept: " + secKeyAccept + Environment.NewLine + Environment.NewLine);            //如果把上一行换成下面两行，才是thewebsocketprotocol-17协议，但居然握手不成功，目前仍没弄明白！            //responseBuilder.Append("Sec-WebSocket-Accept: " + secKeyAccept + Environment.NewLine);            //responseBuilder.Append("Sec-WebSocket-Protocol: chat" + Environment.NewLine);             return Encoding.UTF8.GetBytes(responseBuilder.ToString());        }         /// 
        /// 生成Sec-WebSocket-Accept        /// 
        /// 客户端握手信息        /// Sec-WebSocket-Accept        private static string GetSecKeyAccetp(byte[] handShakeBytes,int bytesLength)        {            string handShakeText = Encoding.UTF8.GetString(handShakeBytes, 0, bytesLength);            string key = string.Empty;            Regex r = new Regex(@"Sec\-WebSocket\-Key:(.*?)\r\n");            Match m = r.Match(handShakeText);            if (m.Groups.Count != 0)            {                key = Regex.Replace(m.Value, @"Sec\-WebSocket\-Key:(.*?)\r\n", "$1").Trim();            }            byte[] encryptionString = SHA1.Create().ComputeHash(Encoding.ASCII.GetBytes(key + "258EAFA5-E914-47DA-95CA-C***B0DC85B11"));            return Convert.ToBase64String(encryptionString);        }         /// 
        /// 解析客户端数据包        /// 
        /// 服务器接收的数据包        /// 有效数据长度        ///         private static string AnalyticData(byte[] recBytes, int recByteLength)        {            if (recByteLength < 2) { return string.Empty; }             bool fin = (recBytes[0] & 0x80) == 0x80; // 1bit，1表示***一帧              if (!fin){                return string.Empty;// 超过一帧暂不处理             }             bool mask_flag = (recBytes[1] & 0x80) == 0x80; // 是否包含掩码              if (!mask_flag){                return string.Empty;// 不包含掩码的暂不处理            }             int payload_len = recBytes[1] & 0x7F; // 数据长度               byte[] masks = new byte[4];            byte[] payload_data;             if (payload_len == 126){                Array.Copy(recBytes, 4, masks, 0, 4);                payload_len = (UInt16)(recBytes[2] << 8 | recBytes[3]);                payload_data = new byte[payload_len];                Array.Copy(recBytes, 8, payload_data, 0, payload_len);             }else if (payload_len == 127){                Array.Copy(recBytes, 10, masks, 0, 4);                byte[] uInt64Bytes = new byte[8];                for (int i = 0; i < 8; i++){                    uInt64Bytes[i] = recBytes[9 - i];                }                UInt64 len = BitConverter.ToUInt64(uInt64Bytes, 0);                 payload_data = new byte[len];                for (UInt64 i = 0; i < len; i++){                    payload_data[i] = recBytes[i + 14];                }            }else{                Array.Copy(recBytes, 2, masks, 0, 4);                payload_data = new byte[payload_len];                Array.Copy(recBytes, 6, payload_data, 0, payload_len);             }             for (var i = 0; i < payload_len; i++){                payload_data[i] = (byte)(payload_data[i] ^ masks[i % 4]);            }                        return Encoding.UTF8.GetString(payload_data);        }          /// 
        /// 打包服务器数据        /// 
        /// 数据        /// 数据包        private static byte[] PackData(string message)        {            byte[] contentBytes = null;            byte[] temp = Encoding.UTF8.GetBytes(message);             if (temp.Length < 126){                contentBytes = new byte[temp.Length + 2];                contentBytes[0] = 0x81;                contentBytes[1] = (byte)temp.Length;                Array.Copy(temp, 0, contentBytes, 2, temp.Length);            }else if (temp.Length < 0xFFFF){                contentBytes = new byte[temp.Length + 4];                contentBytes[0] = 0x81;                contentBytes[1] = 126;                contentBytes[2] = (byte)(temp.Length & 0xFF);                contentBytes[3] = (byte)(temp.Length >> 8 & 0xFF);                Array.Copy(temp, 0, contentBytes, 4, temp.Length);            }else{                // 暂不处理超长内容              }             return contentBytes;        }      }

或者参考这里

ok! 基本上能实现传输文字了,接下来是图像 可以通过base64编码的方式传输 也可以通过二进制传输

HTML5的Canvas 可以实现绘图 然后应该是这样写的

              
                  走你~