web端代碼就是js代碼，C#有兩種方式：使用第三方庫，如Fleck，使用C#原生socket編程實現
1、web端代碼：
<!doctype html><html lang="zh-CN"> <head> <meta charset="UTF-8"> <title>下發網站上文件到學生機</title> <script type="text/javascript"> function callDesktopReceiveFile(button) { var ws = null; if (button.innerHTML == '下發') { button.innerHTML = '取消';
try { if (ws) ws.close(); } catch(e) { console.log(e) }
ws = new WebSocket('ws://127.0.0.1:14567'); //監聽是否連接成功 ws.onopen = function () { console.log('ws連接狀態[成功]：' + ws.readyState); ws.send("content:receiveFile;url:http://127.0.0.1:5500/2023CQGKMNT.dat;"); // ws.close(); console.log('發送消息'); };
// 接聽服務器發回的信息并處理展示 ws.onmessage = function (e) { console.log('接收到來自服務器的消息：' + e.data); // 如果服務器在業務上主動關閉連接，則此處無需再關閉 // if (e.data === 'roger') { // ws.close(); // } };
// 監聽連接關閉事件 ws.onclose = function () { // 監聽整個過程中websocket的狀態 console.log('ws連接狀態[關閉]：' + ws.readyState); };
// 監聽并處理error事件 ws.onerror = function (error) { console.log(error); };
} else if (button.innerHTML == '取消') { try { if (ws) ws.close(); } catch(e) { console.log(e) } button.innerHTML = '下發'; } }</script> </head> <body> <div> <table border="1" cellspacing="0"> <tr> <th>試卷號</th> <th>試卷名稱</th> <th>描述</th> <th>操作</th> </tr> <tr> <td>JCLX01</td> <td>基礎練習一</td> <td>建賬、會計期間設置、部門職員設置、銀行賬戶設置、科目設置等</td> <td><button id="btnDownload" onclick="callDesktopReceiveFile(this)">下發</button></td> </tr> <tr> <td>JCLX02</td> <td>基礎練習二</td> <td>建賬、會計期間設置、部門職員設置、銀行賬戶設置、科目設置等</td> <td><button id="btnDownload" onclick="callDesktopReceiveFile(this)">下發</button></td> </tr> </table>
</div> </body></html>
2、C#端代碼
方式一：使用第三方庫Fleck
參考：chanpinxue.cn/archives/979.html
方式二：使用C#原生socket編程自行實現
using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Windows.Forms;using System.Threading;using U8FileTransfer.TcpHelper;using System.Net.Sockets;using System.Net;using System.Security.Cryptography;
namespace CodeExperiment{ public partial class Form1 : Form { public Form1() { InitializeComponent(); Thread thread = new Thread(websocketListen); thread.IsBackground = true; thread.Start(); }
/// <summary> /// 解析客戶端數據包，防止亂碼 /// </summary> /// <param name="recBytes">服務器接收的數據包</param> /// <param name="recByteLength">有效數據長度</param> /// <returns></returns> private static string AnalyticData(byte[] recBytes, int recByteLength) { if (recByteLength < 2) { return string.Empty; } bool fin = (recBytes[0] & 0x80) == 0x80; // 1bit，1表示最后一幀 if (!fin) { return string.Empty;// 超過一幀暫不處理 } bool mask_flag = (recBytes[1] & 0x80) == 0x80; // 是否包含掩碼 if (!mask_flag) { return string.Empty;// 不包含掩碼的暫不處理 } int payload_len = recBytes[1] & 0x7F; // 數據長度 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); }
/// <summary> /// 打包服務器數據，防止亂碼 /// </summary> /// <param name="message">數據</param> /// <returns>數據包</returns> 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 { // 暫不處理超長內容 } return contentBytes; }
/// <summary> /// 客戶端消息結構化 /// message參數格式為多個key:value鍵值對通過分號拼接組成，示例： /// content:download_and_send;file-url:https://www.a.com/a.zip; /// /// </summary> /// <param name="message"></param> /// <returns></returns> private Dictionary<string, string> ProcessRemoteMessage(string message) { Dictionary<string, string> dic = new Dictionary<string, string>(); if (message.Substring(message.Length - 1, 1) == ";") { message = message.Substring(0, message.Length - 1); } string[] strs = message.Split(';'); if (strs.Length > 0) { Console.WriteLine("- - - - - - - - - - - - - - - - - - -"); foreach (string s in strs) { Console.WriteLine(s); string[] split = s.Split(new char[] { ':' }, 2); Console.WriteLine("[" + split[0] + "][" + split[1] + "]"); dic.Add(split[0], split[1]); } Console.WriteLine("- - - - - - - - - - - - - - - - - - -"); } return dic; }
private void websocketListen() { Socket server = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp); EndPoint endPoint = new IPEndPoint(IPAddress.Any, 14567);//監聽端口 server.Bind(endPoint); server.Listen(10); // 排隊等待連接最大數量10
// 監聽多個客戶端連接 while (true) { Socket client = server.Accept(); Console.WriteLine("有客戶端連上來了");
//接收客戶端發來的HTTP-Header消息 byte[] bytes = new byte[1024]; int len = client.Receive(bytes); string strMessage = Encoding.UTF8.GetString(bytes, 0, len); Console.WriteLine(strMessage);
//獲取Sec-WebSocket-Key，為握手做準備 string[] strings = strMessage.Split('\n'); string strSecWebSocketKey = ""; foreach (var item in strings) { string[] strings1 = item.Split(':'); if (strings1[0] == "Sec-WebSocket-Key") { strSecWebSocketKey = strings1[1].Trim(); } }
//生成服務端Sec-WebSocket-Accept，迎合客戶端的握手請求 byte[] secKeyBytes = SHA1.Create().ComputeHash(Encoding.ASCII.GetBytes(strSecWebSocketKey + "258EAFA5-E914-47DA-95CA-C5AB0DC85B11")); string secKey = Convert.ToBase64String(secKeyBytes);
// 發送給客戶端完成握手(會觸發Websocket的open()回調函數)，針對websocket必須使用以下header string strHeader = ""; strHeader += "HTTP/1.1 101 Switching Protocols" + Environment.NewLine; strHeader += "Upgrade: websocket" + Environment.NewLine; strHeader += "Connection: Upgrade" + Environment.NewLine; strHeader += "Sec-WebSocket-Accept: " + secKey + Environment.NewLine + Environment.NewLine; client.Send(Encoding.UTF8.GetBytes(strHeader));
string remoteFileUrl = null; bool clientClose = false; // 循環接收websocket發來的消息實現雙方交流 while (!clientClose) { //接收客戶端發來的消息 byte[] bytes2 = new byte[1024]; int len2 = client.Receive(bytes2); string strMessage2 = AnalyticData(bytes2, len2); if (strMessage2.Length > 0) { Console.WriteLine("客戶端發來消息：{0}", strMessage2); Dictionary<string, string> messageDic = ProcessRemoteMessage(strMessage2); string content = null; messageDic.TryGetValue("content", out content); Console.WriteLine("message content：" + content); if (content == "receiveFile") { messageDic.TryGetValue("url", out remoteFileUrl); client.Send(PackData("roger")); Console.WriteLine("remoteFileUrl: " + remoteFileUrl); Console.WriteLine("to do invoke download."); // 關閉連接 client.Shutdown(SocketShutdown.Both); client.Close(); clientClose = true; } } else { Console.WriteLine("客戶端關閉了連接"); client.Shutdown(SocketShutdown.Both); client.Close(); } } } } }}
通信雙方都可以主動關閉連接，不管誰關閉連接，對方都能收到消息。client端關閉連接，server端能收到內容長度為0的消息。server端關閉連接，client端會觸發onclose事件。
該文章在 2024/3/30 0:18:44 編輯過
400 186 1886
