CODE-為Self-Hosting ASP.NET Web API加上Log功能

using System;

using System.Collections.Generic;

using System.Linq;

using System.Net.Http;

using System.ServiceModel.Channels;

using System.Text;

using NLog;

namespace MySelfHostWebApi

{

publicclass LogHandler : DelegatingHandler

    {

privatestatic Logger logger = NLog.LogManager.GetCurrentClassLogger();

//REF: http://blog.kkbruce.net/2012/05/aspnet-web-api-8-http-http-message.html

protectedoverride System.Threading.Tasks.Task<HttpResponseMessage> SendAsync(

            HttpRequestMessage request, 

            System.Threading.CancellationToken cancellationToken)

        {

//取得Method、IP、Url等等，稍後寫入NLog

string method = request.Method.ToString();

//REF: http://bit.ly/16lpGKM

//在Self-Hosted模式，透過RemoteEndpointMessageProperty取得IP

string ip = "Unknown";

if (request.Properties.ContainsKey(RemoteEndpointMessageProperty.Name))

                ip = ((RemoteEndpointMessageProperty)

                    request.Properties[RemoteEndpointMessageProperty.Name]).Address;

string url = request.RequestUri.ToString();

returnbase.SendAsync(request, cancellationToken)

                .ContinueWith((task) =>

                {

//Response回傳時，連同StatusCode一起寫入NLog

                    HttpResponseMessage resp = task.Result as HttpResponseMessage;

                    logger.Log(LogLevel.Trace, string.Format("{0} {1} {2} {3}", 

                        ip, method, url, (int)resp.StatusCode));

return resp;

                });

        }

    }

}

//設定路由

            config.Routes.MapHttpRoute("API", 

"{id}",

new { 

                     controller = "download",

                     action = "index"

                 });

//加上LogHandler，記錄存取Log

            config.MessageHandlers.Add(new LogHandler());

            httpServer = new HttpSelfHostServer(config);