javascript - 网络套接字只说一种方式

Question

我正在尝试通过 Web 套接字获取 C# 应用程序和网页。我从各种来源抄袭了一些代码，但我只能让浏览器向 C# 应用程序发送消息，而不是相反。这对我来说是一个新领域，所以我在黑暗中摸索了一下。

这是C#：

using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Text.RegularExpressions;

class Server
{
    public static void Main()
    {
        string ip = "127.0.0.1";
        int port = 8082;
        var server = new TcpListener(IPAddress.Parse(ip), port);

        server.Start();
        Console.WriteLine("Server has started on {0}:{1}, Waiting for a connection...", ip, port);

        TcpClient client = server.AcceptTcpClient();

        Console.WriteLine("A client connected.");

        NetworkStream stream = client.GetStream();

        // enter to an infinite cycle to be able to handle every change in stream
        while (true)
        {
            while (!stream.DataAvailable) ;
            while (client.Available < 3) ; // match against "get"

            byte[] bytes = new byte[client.Available];
            stream.Read(bytes, 0, client.Available);
            string s = Encoding.UTF8.GetString(bytes);

            if (Regex.IsMatch(s, "^GET", RegexOptions.IgnoreCase))
            {
                Console.WriteLine("=====Handshaking from client=====\n{0}", s);

                // 1. Obtain the value of the "Sec-WebSocket-Key" request header without any leading or trailing whitespace
                // 2. Concatenate it with "258EAFA5-E914-47DA-95CA-C5AB0DC85B11" (a special GUID specified by RFC 6455)
                // 3. Compute SHA-1 and Base64 hash of the new value
                // 4. Write the hash back as the value of "Sec-WebSocket-Accept" response header in an HTTP response
                string swk = Regex.Match(s, "Sec-WebSocket-Key: (.*)").Groups[1].Value.Trim();
                string swka = swk + "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
                byte[] swkaSha1 = System.Security.Cryptography.SHA1.Create().ComputeHash(Encoding.UTF8.GetBytes(swka));
                string swkaSha1Base64 = Convert.ToBase64String(swkaSha1);

                // HTTP/1.1 defines the sequence CR LF as the end-of-line marker
                byte[] response = Encoding.UTF8.GetBytes(
                    "HTTP/1.1 101 Switching Protocols\r\n" +
                    "Connection: Upgrade\r\n" +
                    "Upgrade: websocket\r\n" +
                    "Sec-WebSocket-Accept: " + swkaSha1Base64 + "\r\n\r\n");

                stream.Write(response, 0, response.Length);
            }
            else
            {
                bool fin = (bytes[0] & 0b10000000) != 0,
                    mask = (bytes[1] & 0b10000000) != 0; // must be true, "All messages from the client to the server have this bit set"

                int opcode = bytes[0] & 0b00001111, // expecting 1 - text message
                    msglen = bytes[1] - 128, // & 0111 1111
                    offset = 2;

                if (msglen == 126)
                {
                    // was ToUInt16(bytes, offset) but the result is incorrect
                    msglen = BitConverter.ToUInt16(new byte[] { bytes[3], bytes[2] }, 0);
                    offset = 4;
                }
                else if (msglen == 127)
                {
                    Console.WriteLine("TODO: msglen == 127, needs qword to store msglen");
                    // i don't really know the byte order, please edit this
                    // msglen = BitConverter.ToUInt64(new byte[] { bytes[5], bytes[4], bytes[3], bytes[2], bytes[9], bytes[8], bytes[7], bytes[6] }, 0);
                    // offset = 10;
                }

                if (msglen == 0)
                    Console.WriteLine("msglen == 0");
                else if (mask)
                {
                    byte[] decoded = new byte[msglen];
                    byte[] masks = new byte[4] { bytes[offset], bytes[offset + 1], bytes[offset + 2], bytes[offset + 3] };
                    offset += 4;

                    for (int i = 0; i < msglen; ++i)
                        decoded[i] = (byte)(bytes[offset + i] ^ masks[i % 4]);

                    string text = Encoding.UTF8.GetString(decoded);
                    Console.WriteLine("{0}", text);
                }
                else
                    Console.WriteLine("mask bit not set");

                Console.WriteLine();

                string yourmessage = "Ta much";
                Byte[] sendBytes = Encoding.UTF8.GetBytes(yourmessage);
                Console.WriteLine("Sending back : " + yourmessage);
                stream.Write(sendBytes, 0, sendBytes.Length);
            }
        }
    }
}

这是网页：

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8" />
    <style>
        textarea { vertical-align: bottom; }
        #output { overflow: auto; border:solid 1px #F00; width:500px; height:300px;padding:5px;}
        #output > p { overflow-wrap: break-word; }
        #output span { color: blue; }
        #output span.error { color: red; }
    </style>
</head>
<body>
<h2>WebSocket Test</h2>
<textarea cols=60 rows=6></textarea>
<button>send</button><br /><br />
<div id=output></div>
<script>
    // http://www.websocket.org/echo.html

    var button = document.querySelector("button"),
        output = document.querySelector("#output"),
        textarea = document.querySelector("textarea"),
        // wsUri = "ws://echo.websocket.org/",
        wsUri = "ws://127.0.0.1:8082/",
        websocket = null;

    try
    {
        websocket = new WebSocket(wsUri);
    }
    catch(e)
    {
        console.log("No connect");
    }

    button.addEventListener("click", onClickButton);

    websocket.onopen = function (e) {
        writeToScreen("CONNECTED");
        doSend("WebSocket rocks");
    };

    websocket.onclose = function (e) {
        writeToScreen("DISCONNECTED");
    };

    websocket.onmessage = function (e) {
        console.log(e);
        writeToScreen("<span>RESPONSE: " + e.data + "</span>");
    };

    websocket.onerror = function (e) {
        writeToScreen("<span class=error>ERROR:</span> " + e.data);
    };

    function doSend(message) {
        writeToScreen("SENT: " + message);
        websocket.send(message);
    }

    function writeToScreen(message) {
        output.insertAdjacentHTML("afterbegin", "<p>" + message + "</p>");
    }

    function onClickButton() {
        var text = textarea.value;

        text && doSend(text);
        textarea.value = "";
        textarea.focus();
    }
</script>
</body>
</html>

我期待 C# 中的最后一行代码被 Javascript 中的 onmessage 处理程序拾取，但什么都没有发生。有人可以帮我吗？

笔记：

我正在使用 Firefox，因为 Chrome 不喜欢本地主机上的 ws。

标签： javascriptc#websocket