创建"Hello World"WebSocket示例
Ton*_*Nam 79 javascript c# websocket
我不明白为什么我不能使下面的代码工作.我想用JavaScript连接到我的服务器控制台应用程序.然后将数据发送到服务器.
这是服务器代码:
static void Main(string[] args)
{
TcpListener server = new TcpListener(IPAddress.Parse("127.0.0.1"), 9998);
server.Start();
var client = server.AcceptTcpClient();
var stream = client.GetStream();
while (true)
{
var buffer = new byte[1024];
// wait for data to be received
var bytesRead = stream.Read(buffer, 0, buffer.Length);
var r = System.Text.Encoding.UTF8.GetString(buffer);
// write received data to the console
Console.WriteLine(r.Substring(0, bytesRead));
}
}
这是JavaScript:
var ws = new WebSocket("ws://localhost:9998/service");
ws.onopen = function () {
ws.send("Hello World"); // I WANT TO SEND THIS MESSAGE TO THE SERVER!!!!!!!!
};
ws.onmessage = function (evt) {
var received_msg = evt.data;
alert("Message is received...");
};
ws.onclose = function () {
// websocket is closed.
alert("Connection is closed...");
};
当我运行该代码时,会发生以下情况:
请注意,当我运行JavaScript时,服务器接受并成功建立连接.JavaScript无法发送数据.每当我放置send方法时,即使建立了连接也不会发送.我怎样才能做到这一点？
mok*_*oka 65
WebSockets是依赖于TCP流连接的协议.虽然WebSockets是基于消息的协议.
如果你想实现自己的协议,那么我建议使用最新和稳定的规范(针对18/04/12)RFC 6455.该规范包含有关握手和成帧的所有必要信息.以及关于从浏览器端以及从服务器端行为的场景的大部分描述.强烈建议在实现代码时遵循有关服务器端的建议.
简而言之,我会描述使用WebSockets,如下所示:
创建服务器Socket(System.Net.Sockets)将其绑定到特定端口,并通过异步接受连接继续侦听.像这样的东西:
Socket serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.IP); serverSocket.Bind(new IPEndPoint(IPAddress.Any, 8080)); serverSocket.Listen(128); serverSocket.BeginAccept(null, 0, OnAccept, null);
你应该接受将实现握手的函数"OnAccept".如果系统意味着每秒处理大量连接,它将来必须在另一个线程中.
private void OnAccept(IAsyncResult result) { try { Socket client = null; if (serverSocket != null && serverSocket.IsBound) { client = serverSocket.EndAccept(result); } if (client != null) { /* Handshaking and managing ClientSocket */ } } catch(SocketException exception) { } finally { if (serverSocket != null && serverSocket.IsBound) { serverSocket.BeginAccept(null, 0, OnAccept, null); } } }建立连接后,您必须进行握手.根据规范1.3打开握手,在建立连接后,您将收到带有一些信息的基本HTTP请求.例:
GET /chat HTTP/1.1 Host: server.example.com Upgrade: websocket Connection: Upgrade Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ== Origin: http://example.com Sec-WebSocket-Protocol: chat, superchat Sec-WebSocket-Version: 13
此示例基于协议13的版本.请记住,旧版本有一些差异,但大多数最新版本是交叉兼容的.不同的浏览器可能会向您发送一些其他数 例如浏览器和操作系统详细信息,缓存等.
根据所提供的握手的细节,你必须产生应答线,他们大多是相同的,但会包含Accpet头-Key,即基于提供二段WebSocket的密钥.在规范1.3中,清楚地描述了如何生成响应密钥.这是我一直用于V13的功能:
static private string guid = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"; private string AcceptKey(ref string key) { string longKey = key + guid; SHA1 sha1 = SHA1CryptoServiceProvider.Create(); byte[] hashBytes = sha1.ComputeHash(System.Text.Encoding.ASCII.GetBytes(longKey)); return Convert.ToBase64String(hashBytes); }握手答案看起来像这样:
HTTP/1.1 101 Switching Protocols Upgrade: websocket Connection: Upgrade Sec-WebSocket-Accept: s3pPLMBiTxaQ9kYGzzhZRbK+xOo=
但是,接受密钥必须是基于客户端提供的密钥和我之前提供的方法AcceptKey生成的密钥.同样,确保在接受键的最后一个字符后面放两行"\ r \n\r \n".
- 在从服务器发送握手应答后,客户端应触发" onopen "功能,这意味着您可以在之后发送消息.
- 消息不以原始格式发送,但它们具有数据框架.从客户端到服务器以及基于消息头中提供的4个字节实现数据屏蔽.虽然从服务器到客户端,您不需要对数据应用屏蔽.阅读第5节.规范中的数据框架.这是我自己实现的复制粘贴.它不是现成的代码,必须进行修改,我发布它只是为了给出一个想法和WebSocket框架读/写的整体逻辑.转到此链接.
- 实现成帧后,请确保使用套接字以正确的方式接收数据.例如,为了防止某些消息合并为一个消息,因为TCP仍然是基于流的协议.这意味着您必须只读取特定的字节数.消息长度始终基于标题,并在标题中提供数据长度详细信息.因此,当您从Socket接收数据时,首先接收2个字节,根据成帧规范从头部获取详细信息,然后如果掩码提供另外4个字节,则长度可能是基于数据长度的1,4或8个字节.在数据之后它自我.阅读后,应用demasking,您的消息数据就可以使用了.
- 您可能希望使用某些数据协议,我建议使用JSON,因为流量经济并且在JavaScript中易于在客户端使用.对于服务器端,您可能需要检查一些解析器.有很多,谷歌可以真的很有帮助.
实现自己的WebSockets协议肯定会带来一些好处和丰富的经验,以及自己对协议的控制.但是你必须花一些时间来做这件事,并确保实施非常可靠.
同时你可能会看到谷歌(再次)有足够的解决方案.
我在任何地方都找不到一个简单的工作示例（截至 1 月 19 日），所以这里是一个更新版本。我有 chrome 版本 71.0.3578.98。
C# Websocket 服务器：
using System;
using System.Text;
using System.Net;
using System.Net.Sockets;
using System.Security.Cryptography;
namespace WebSocketServer
{
class Program
{
static Socket serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.IP);
static private string guid = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
static void Main(string[] args)
{
serverSocket.Bind(new IPEndPoint(IPAddress.Any, 8080));
serverSocket.Listen(1); //just one socket
serverSocket.BeginAccept(null, 0, OnAccept, null);
Console.Read();
}
private static void OnAccept(IAsyncResult result)
{
byte[] buffer = new byte[1024];
try
{
Socket client = null;
string headerResponse = "";
if (serverSocket != null && serverSocket.IsBound)
{
client = serverSocket.EndAccept(result);
var i = client.Receive(buffer);
headerResponse = (System.Text.Encoding.UTF8.GetString(buffer)).Substring(0, i);
// write received data to the console
Console.WriteLine(headerResponse);
Console.WriteLine("=====================");
}
if (client != null)
{
/* Handshaking and managing ClientSocket */
var key = headerResponse.Replace("ey:", "`")
.Split('`')[1] // dGhlIHNhbXBsZSBub25jZQ== \r\n .......
.Replace("\r", "").Split('\n')[0] // dGhlIHNhbXBsZSBub25jZQ==
.Trim();
// key should now equal dGhlIHNhbXBsZSBub25jZQ==
var test1 = AcceptKey(ref key);
var newLine = "\r\n";
var response = "HTTP/1.1 101 Switching Protocols" + newLine
+ "Upgrade: websocket" + newLine
+ "Connection: Upgrade" + newLine
+ "Sec-WebSocket-Accept: " + test1 + newLine + newLine
//+ "Sec-WebSocket-Protocol: chat, superchat" + newLine
//+ "Sec-WebSocket-Version: 13" + newLine
;
client.Send(System.Text.Encoding.UTF8.GetBytes(response));
var i = client.Receive(buffer); // wait for client to send a message
string browserSent = GetDecodedData(buffer, i);
Console.WriteLine("BrowserSent: " + browserSent);
Console.WriteLine("=====================");
//now send message to client
client.Send(GetFrameFromString("This is message from server to client."));
System.Threading.Thread.Sleep(10000);//wait for message to be sent
}
}
catch (SocketException exception)
{
throw exception;
}
finally
{
if (serverSocket != null && serverSocket.IsBound)
{
serverSocket.BeginAccept(null, 0, OnAccept, null);
}
}
}
public static T[] SubArray<T>(T[] data, int index, int length)
{
T[] result = new T[length];
Array.Copy(data, index, result, 0, length);
return result;
}
private static string AcceptKey(ref string key)
{
string longKey = key + guid;
byte[] hashBytes = ComputeHash(longKey);
return Convert.ToBase64String(hashBytes);
}
static SHA1 sha1 = SHA1CryptoServiceProvider.Create();
private static byte[] ComputeHash(string str)
{
return sha1.ComputeHash(System.Text.Encoding.ASCII.GetBytes(str));
}
//Needed to decode frame
public static string GetDecodedData(byte[] buffer, int length)
{
byte b = buffer[1];
int dataLength = 0;
int totalLength = 0;
int keyIndex = 0;
if (b - 128 <= 125)
{
dataLength = b - 128;
keyIndex = 2;
totalLength = dataLength + 6;
}
if (b - 128 == 126)
{
dataLength = BitConverter.ToInt16(new byte[] { buffer[3], buffer[2] }, 0);
keyIndex = 4;
totalLength = dataLength + 8;
}
if (b - 128 == 127)
{
dataLength = (int)BitConverter.ToInt64(new byte[] { buffer[9], buffer[8], buffer[7], buffer[6], buffer[5], buffer[4], buffer[3], buffer[2] }, 0);
keyIndex = 10;
totalLength = dataLength + 14;
}
if (totalLength > length)
throw new Exception("The buffer length is small than the data length");
byte[] key = new byte[] { buffer[keyIndex], buffer[keyIndex + 1], buffer[keyIndex + 2], buffer[keyIndex + 3] };
int dataIndex = keyIndex + 4;
int count = 0;
for (int i = dataIndex; i < totalLength; i++)
{
buffer[i] = (byte)(buffer[i] ^ key[count % 4]);
count++;
}
return Encoding.ASCII.GetString(buffer, dataIndex, dataLength);
}
//function to create frames to send to client
/// <summary>
/// Enum for opcode types
/// </summary>
public enum EOpcodeType
{
/* Denotes a continuation code */
Fragment = 0,
/* Denotes a text code */
Text = 1,
/* Denotes a binary code */
Binary = 2,
/* Denotes a closed connection */
ClosedConnection = 8,
/* Denotes a ping*/
Ping = 9,
/* Denotes a pong */
Pong = 10
}
/// <summary>Gets an encoded websocket frame to send to a client from a string</summary>
/// <param name="Message">The message to encode into the frame</param>
/// <param name="Opcode">The opcode of the frame</param>
/// <returns>Byte array in form of a websocket frame</returns>
public static byte[] GetFrameFromString(string Message, EOpcodeType Opcode = EOpcodeType.Text)
{
byte[] response;
byte[] bytesRaw = Encoding.Default.GetBytes(Message);
byte[] frame = new byte[10];
long indexStartRawData = -1;
long length = (long)bytesRaw.Length;
frame[0] = (byte)(128 + (int)Opcode);
if (length <= 125)
{
frame[1] = (byte)length;
indexStartRawData = 2;
}
else if (length >= 126 && length <= 65535)
{
frame[1] = (byte)126;
frame[2] = (byte)((length >> 8) & 255);
frame[3] = (byte)(length & 255);
indexStartRawData = 4;
}
else
{
frame[1] = (byte)127;
frame[2] = (byte)((length >> 56) & 255);
frame[3] = (byte)((length >> 48) & 255);
frame[4] = (byte)((length >> 40) & 255);
frame[5] = (byte)((length >> 32) & 255);
frame[6] = (byte)((length >> 24) & 255);
frame[7] = (byte)((length >> 16) & 255);
frame[8] = (byte)((length >> 8) & 255);
frame[9] = (byte)(length & 255);
indexStartRawData = 10;
}
response = new byte[indexStartRawData + length];
long i, reponseIdx = 0;
//Add the frame bytes to the reponse
for (i = 0; i < indexStartRawData; i++)
{
response[reponseIdx] = frame[i];
reponseIdx++;
}
//Add the data bytes to the response
for (i = 0; i < length; i++)
{
response[reponseIdx] = bytesRaw[i];
reponseIdx++;
}
return response;
}
}
}
客户端 html 和 javascript：
using System;
using System.Text;
using System.Net;
using System.Net.Sockets;
using System.Security.Cryptography;
namespace WebSocketServer
{
class Program
{
static Socket serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.IP);
static private string guid = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
static void Main(string[] args)
{
serverSocket.Bind(new IPEndPoint(IPAddress.Any, 8080));
serverSocket.Listen(1); //just one socket
serverSocket.BeginAccept(null, 0, OnAccept, null);
Console.Read();
}
private static void OnAccept(IAsyncResult result)
{
byte[] buffer = new byte[1024];
try
{
Socket client = null;
string headerResponse = "";
if (serverSocket != null && serverSocket.IsBound)
{
client = serverSocket.EndAccept(result);
var i = client.Receive(buffer);
headerResponse = (System.Text.Encoding.UTF8.GetString(buffer)).Substring(0, i);
// write received data to the console
Console.WriteLine(headerResponse);
Console.WriteLine("=====================");
}
if (client != null)
{
/* Handshaking and managing ClientSocket */
var key = headerResponse.Replace("ey:", "`")
.Split('`')[1] // dGhlIHNhbXBsZSBub25jZQ== \r\n .......
.Replace("\r", "").Split('\n')[0] // dGhlIHNhbXBsZSBub25jZQ==
.Trim();
// key should now equal dGhlIHNhbXBsZSBub25jZQ==
var test1 = AcceptKey(ref key);
var newLine = "\r\n";
var response = "HTTP/1.1 101 Switching Protocols" + newLine
+ "Upgrade: websocket" + newLine
+ "Connection: Upgrade" + newLine
+ "Sec-WebSocket-Accept: " + test1 + newLine + newLine
//+ "Sec-WebSocket-Protocol: chat, superchat" + newLine
//+ "Sec-WebSocket-Version: 13" + newLine
;
client.Send(System.Text.Encoding.UTF8.GetBytes(response));
var i = client.Receive(buffer); // wait for client to send a message
string browserSent = GetDecodedData(buffer, i);
Console.WriteLine("BrowserSent: " + browserSent);
Console.WriteLine("=====================");
//now send message to client
client.Send(GetFrameFromString("This is message from server to client."));
System.Threading.Thread.Sleep(10000);//wait for message to be sent
}
}
catch (SocketException exception)
{
throw exception;
}
finally
{
if (serverSocket != null && serverSocket.IsBound)
{
serverSocket.BeginAccept(null, 0, OnAccept, null);
}
}
}
public static T[] SubArray<T>(T[] data, int index, int length)
{
T[] result = new T[length];
Array.Copy(data, index, result, 0, length);
return result;
}
private static string AcceptKey(ref string key)
{
string longKey = key + guid;
byte[] hashBytes = ComputeHash(longKey);
return Convert.ToBase64String(hashBytes);
}
static SHA1 sha1 = SHA1CryptoServiceProvider.Create();
private static byte[] ComputeHash(string str)
{
return sha1.ComputeHash(System.Text.Encoding.ASCII.GetBytes(str));
}
//Needed to decode frame
public static string GetDecodedData(byte[] buffer, int length)
{
byte b = buffer[1];
int dataLength = 0;
int totalLength = 0;
int keyIndex = 0;
if (b - 128 <= 125)
{
dataLength = b - 128;
keyIndex = 2;
totalLength = dataLength + 6;
}
if (b - 128 == 126)
{
dataLength = BitConverter.ToInt16(new byte[] { buffer[3], buffer[2] }, 0);
keyIndex = 4;
totalLength = dataLength + 8;
}
if (b - 128 == 127)
{
dataLength = (int)BitConverter.ToInt64(new byte[] { buffer[9], buffer[8], buffer[7], buffer[6], buffer[5], buffer[4], buffer[3], buffer[2] }, 0);
keyIndex = 10;
totalLength = dataLength + 14;
}
if (totalLength > length)
throw new Exception("The buffer length is small than the data length");
byte[] key = new byte[] { buffer[keyIndex], buffer[keyIndex + 1], buffer[keyIndex + 2], buffer[keyIndex + 3] };
int dataIndex = keyIndex + 4;
int count = 0;
for (int i = dataIndex; i < totalLength; i++)
{
buffer[i] = (byte)(buffer[i] ^ key[count % 4]);
count++;
}
return Encoding.ASCII.GetString(buffer, dataIndex, dataLength);
}
//function to create frames to send to client
/// <summary>
/// Enum for opcode types
/// </summary>
public enum EOpcodeType
{
/* Denotes a continuation code */
Fragment = 0,
/* Denotes a text code */
Text = 1,
/* Denotes a binary code */
Binary = 2,
/* Denotes a closed connection */
ClosedConnection = 8,
/* Denotes a ping*/
Ping = 9,
/* Denotes a pong */
Pong = 10
}
/// <summary>Gets an encoded websocket frame to send to a client from a string</summary>
/// <param name="Message">The message to encode into the frame</param>
/// <param name="Opcode">The opcode of the frame</param>
/// <returns>Byte array in form of a websocket frame</returns>
public static byte[] GetFrameFromString(string Message, EOpcodeType Opcode = EOpcodeType.Text)
{
byte[] response;
byte[] bytesRaw = Encoding.Default.GetBytes(Message);
byte[] frame = new byte[10];
long indexStartRawData = -1;
long length = (long)bytesRaw.Length;
frame[0] = (byte)(128 + (int)Opcode);
if (length <= 125)
{
frame[1] = (byte)length;
indexStartRawData = 2;
}
else if (length >= 126 && length <= 65535)
{
frame[1] = (byte)126;
frame[2] = (byte)((length >> 8) & 255);
frame[3] = (byte)(length & 255);
indexStartRawData = 4;
}
else
{
frame[1] = (byte)127;
frame[2] = (byte)((length >> 56) & 255);
frame[3] = (byte)((length >> 48) & 255);
frame[4] = (byte)((length >> 40) & 255);
frame[5] = (byte)((length >> 32) & 255);
frame[6] = (byte)((length >> 24) & 255);
frame[7] = (byte)((length >> 16) & 255);
frame[8] = (byte)((length >> 8) & 255);
frame[9] = (byte)(length & 255);
indexStartRawData = 10;
}
response = new byte[indexStartRawData + length];
long i, reponseIdx = 0;
//Add the frame bytes to the reponse
for (i = 0; i < indexStartRawData; i++)
{
response[reponseIdx] = frame[i];
reponseIdx++;
}
//Add the data bytes to the response
for (i = 0; i < length; i++)
{
response[reponseIdx] = bytesRaw[i];
reponseIdx++;
}
return response;
}
}
}
(代表OP发表答复).
我现在能够发送数据.这是我的新版程序,感谢您的答案和@Maksims Mihejevs的代码.
服务器
using System;
using System.Net.Sockets;
using System.Net;
using System.Security.Cryptography;
using System.Threading;
namespace ConsoleApplication1
{
class Program
{
static Socket serverSocket = new Socket(AddressFamily.InterNetwork,
SocketType.Stream, ProtocolType.IP);
static private string guid = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
static void Main(string[] args)
{
serverSocket.Bind(new IPEndPoint(IPAddress.Any, 8080));
serverSocket.Listen(128);
serverSocket.BeginAccept(null, 0, OnAccept, null);
Console.Read();
}
private static void OnAccept(IAsyncResult result)
{
byte[] buffer = new byte[1024];
try
{
Socket client = null;
string headerResponse = "";
if (serverSocket != null && serverSocket.IsBound)
{
client = serverSocket.EndAccept(result);
var i = client.Receive(buffer);
headerResponse = (System.Text.Encoding.UTF8.GetString(buffer)).Substring(0,i);
// write received data to the console
Console.WriteLine(headerResponse);
}
if (client != null)
{
/* Handshaking and managing ClientSocket */
var key = headerResponse.Replace("ey:", "`")
.Split('`')[1] // dGhlIHNhbXBsZSBub25jZQ== \r\n .......
.Replace("\r", "").Split('\n')[0] // dGhlIHNhbXBsZSBub25jZQ==
.Trim();
// key should now equal dGhlIHNhbXBsZSBub25jZQ==
var test1 = AcceptKey(ref key);
var newLine = "\r\n";
var response = "HTTP/1.1 101 Switching Protocols" + newLine
+ "Upgrade: websocket" + newLine
+ "Connection: Upgrade" + newLine
+ "Sec-WebSocket-Accept: " + test1 + newLine + newLine
//+ "Sec-WebSocket-Protocol: chat, superchat" + newLine
//+ "Sec-WebSocket-Version: 13" + newLine
;
// which one should I use? none of them fires the onopen method
client.Send(System.Text.Encoding.UTF8.GetBytes(response));
var i = client.Receive(buffer); // wait for client to send a message
// once the message is received decode it in different formats
Console.WriteLine(Convert.ToBase64String(buffer).Substring(0, i));
Console.WriteLine("\n\nPress enter to send data to client");
Console.Read();
var subA = SubArray<byte>(buffer, 0, i);
client.Send(subA);
Thread.Sleep(10000);//wait for message to be send
}
}
catch (SocketException exception)
{
throw exception;
}
finally
{
if (serverSocket != null && serverSocket.IsBound)
{
serverSocket.BeginAccept(null, 0, OnAccept, null);
}
}
}
public static T[] SubArray<T>(T[] data, int index, int length)
{
T[] result = new T[length];
Array.Copy(data, index, result, 0, length);
return result;
}
private static string AcceptKey(ref string key)
{
string longKey = key + guid;
byte[] hashBytes = ComputeHash(longKey);
return Convert.ToBase64String(hashBytes);
}
static SHA1 sha1 = SHA1CryptoServiceProvider.Create();
private static byte[] ComputeHash(string str)
{
return sha1.ComputeHash(System.Text.Encoding.ASCII.GetBytes(str));
}
}
}
JavaScript的:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<script type="text/javascript">
function connect() {
var ws = new WebSocket("ws://localhost:8080/service");
ws.onopen = function () {
alert("About to send data");
ws.send("Hello World"); // I WANT TO SEND THIS MESSAGE TO THE SERVER!!!!!!!!
alert("Message sent!");
};
ws.onmessage = function (evt) {
alert("About to receive data");
var received_msg = evt.data;
alert("Message received = "+received_msg);
};
ws.onclose = function () {
// websocket is closed.
alert("Connection is closed...");
};
};
</script>
</head>
<body style="font-size:xx-large" >
<div>
<a href="#" onclick="connect()">Click here to start</a></div>
</body>
</html>
当我运行该代码时,我能够从客户端和服务器发送和接收数据.唯一的问题是消息在到达服务器时会被加密.以下是程序运行的步骤:
请注意来自客户端的消息是如何加密的.
- 您的示例有些错误,当我按下Enter键时,Connection将关闭. (2认同)
WebSockets 使用涉及客户端和服务器之间的握手的协议来实现.我不认为它们的工作方式与普通插座非常相似.阅读协议,让您的应用程序进行讨论.或者,使用现有的WebSocket库或具有WebSocket API的 .Net4.5beta .
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