HttpListener提供一個簡單的、可通過編程方式控制的 HTTP 協議偵聽器.使用它可以很容易的提供一些Http服務，而無需啟動IIS這類大型服務程序。使用HttpListener的方法流程很簡單：主要分為以下幾步 

1.創建一個HTTP偵聽器對象并初始化 

2.添加需要監聽的URI 前綴 

3.開始偵聽來自客戶端的請求 

4.處理客戶端的Http請求 

5.關閉HTTP偵聽器 

例如：我們要實現一個簡單Http服務，進行文件的下載，或者進行一些其他的操作，例如要發送郵件，使用HttpListener監聽，處理郵件隊列，避免在網站上的同步等待。以及獲取一些緩存的數據等等行為 

using System;using System.Collections.Generic;using System.Linq;using System.Net;using System.Text;using System.Threading;using System.Web;using System.IO;using Newtonsoft.Json;namespace HttpListenerApp{ /// <summary> /// HttpRequest邏輯處理 /// </summary> public class HttpProvider {  private static HttpListener httpFiledownload; //文件下載處理請求監聽  private static HttpListener httOtherRequest; //其他超做請求監聽  /// <summary>  /// 開啟HttpListener監聽  /// </summary>  public static void Init()  {   httpFiledownload = new HttpListener(); //創建監聽實例   httpFiledownload.Prefixes.Add("http://10.0.0.217:20009/FileManageApi/Download/"); //添加監聽地址 注意是以/結尾。   httpFiledownload.Start(); //允許該監聽地址接受請求的傳入。   Thread ThreadhttpFiledownload = new Thread(new ThreadStart(GethttpFiledownload)); //創建開啟一個線程監聽該地址得請求   ThreadhttpFiledownload.Start();   httOtherRequest = new HttpListener();   httOtherRequest.Prefixes.Add("http://10.0.0.217:20009/BehaviorApi/EmailSend/"); //添加監聽地址 注意是以/結尾。   httOtherRequest.Start(); //允許該監聽地址接受請求的傳入。   Thread ThreadhttOtherRequest = new Thread(new ThreadStart(GethttOtherRequest));   ThreadhttOtherRequest.Start();  }  /// <summary>  /// 執行文件下載處理請求監聽行為  /// </summary>  public static void GethttpFiledownload()  {   while (true)   {    HttpListenerContext requestContext = httpFiledownload.GetContext(); //接受到新的請求    try    {     //reecontext 為開啟線程傳入的 requestContext請求對象     Thread subthread = new Thread(new ParameterizedThreadStart((reecontext) =>       {      Console.WriteLine("執行文件處理請求監聽行為");      var request = (HttpListenerContext)reecontext;      var image = HttpUtility.UrlDecode(request.Request.QueryString["imgname"]); //接受GET請求過來的參數；      string filepath = AppDomain.CurrentDomain.BaseDirectory + image;      if (!File.Exists(filepath))      {       filepath = AppDomain.CurrentDomain.BaseDirectory + "default.jpg";  //下載默認圖片      }      using (FileStream fs = new FileStream(filepath, FileMode.Open, FileAccess.Read))      {       byte[] buffer = new byte[fs.Length];       fs.Read(buffer, 0, (int)fs.Length); //將文件讀到緩存區       request.Response.StatusCode = 200;       request.Response.Headers.Add("Access-Control-Allow-Origin", "*");       request.Response.ContentType = "image/jpg";        request.Response.ContentLength64 = buffer.Length;       var output = request.Response.OutputStream; //獲取請求流       output.Write(buffer, 0, buffer.Length);  //將緩存區的字節數寫入當前請求流返回       output.Close();      }     }));     subthread.Start(requestContext); //開啟處理線程處理下載文件    }    catch (Exception ex)    {     try     {      requestContext.Response.StatusCode = 500;      requestContext.Response.ContentType = "application/text";      requestContext.Response.ContentEncoding = Encoding.UTF8;      byte[] buffer = System.Text.Encoding.UTF8.GetBytes("System Error");      //對客戶端輸出相應信息.      requestContext.Response.ContentLength64 = buffer.Length;      System.IO.Stream output = requestContext.Response.OutputStream;      output.Write(buffer, 0, buffer.Length);      //關閉輸出流，釋放相應資源      output.Close();     }     catch { }    }   }  }  /// <summary>  /// 執行其他超做請求監聽行為  /// </summary>  public static void GethttOtherRequest()  {   while (true)   {    HttpListenerContext requestContext = httOtherRequest.GetContext(); //接受到新的請求    try    {     //reecontext 為開啟線程傳入的 requestContext請求對象     Thread subthread = new Thread(new ParameterizedThreadStart((reecontext) =>     {      Console.WriteLine("執行其他超做請求監聽行為");      var request = (HttpListenerContext)reecontext;      var msg = HttpUtility.UrlDecode(request.Request.QueryString["behavior"]); //接受GET請求過來的參數；      //在此處執行你需要進行的操作>>比如什么緩存數據讀取，隊列消息處理，郵件消息隊列添加等等。      request.Response.StatusCode = 200;      request.Response.Headers.Add("Access-Control-Allow-Origin", "*");      request.Response.ContentType = "application/json";      requestContext.Response.ContentEncoding = Encoding.UTF8;      byte[] buffer = System.Text.Encoding.UTF8.GetBytes(JsonConvert.SerializeObject(new { success = true, behavior = msg }));      request.Response.ContentLength64 = buffer.Length;      var output = request.Response.OutputStream;      output.Write(buffer, 0, buffer.Length);      output.Close();     }));     subthread.Start(requestContext); //開啟處理線程處理下載文件    }    catch (Exception ex)    {     try     {      requestContext.Response.StatusCode = 500;      requestContext.Response.ContentType = "application/text";      requestContext.Response.ContentEncoding = Encoding.UTF8;      byte[] buffer = System.Text.Encoding.UTF8.GetBytes("System Error");      //對客戶端輸出相應信息.      requestContext.Response.ContentLength64 = buffer.Length;      System.IO.Stream output = requestContext.Response.OutputStream;      output.Write(buffer, 0, buffer.Length);      //關閉輸出流，釋放相應資源      output.Close();     }     catch { }    }   }  } }}