public class MonitorApiAttribute : ActionFilterAttribute

    {

        private static readonly string key = "enterTime";

        public override void OnActionExecuted(HttpActionExecutedContext filterContext)

        {

            try

            {

                object beginTime = null;

                if (filterContext.Request.Properties.TryGetValue(key, out beginTime))

                {

                    var user = HttpContext.Current.User as UserInfo;//登录时储存的User

                    var indentify = user != null ? user.Id.ToString() : null;

                    MonitorApiHelper.Monitor(beginTime, filterContext.Request, filterContext.Response, indentify);

                }

            }

            catch (Exception)

            {

            }

            base.OnActionExecuted(filterContext);

        }

        public override void OnActionExecuting(HttpActionContext actionContext)

        {

            actionContext.Request.Properties[key] = DateTime.Now.ToBinary();

            base.OnActionExecuting(actionContext);

        }

    }

public class MonitorApiHelper

    {

        public static async void Monitor(object beginTime, HttpRequestMessage httpRequestMessage, HttpResponseMessage httpResponseMessage, string indentify = "", string moduleId = "")

        {

            DateTime time = DateTime.FromBinary(Convert.ToInt64(beginTime));

            var responseTime = Convert.ToInt32((DateTime.Now - time).TotalMilliseconds);

            var appId = "myapp";

            var clientType = 0;

            var responseStatus = 0;

            var request = HttpContext.Current.Request;

            var browerVersion = request.UserAgent;

            var clientIP = request.UserHostAddress;

            var serviceName = request.Url.AbsoluteUri;

            var requestType = MethodConver(request.HttpMethod);

            var inputParams = ReadStream(await httpRequestMessage.Content.ReadAsStreamAsync());

            var outputParams = ReadStream(await httpResponseMessage.Content.ReadAsStreamAsync());

            //在这里使用以上变量记录日志操作

        }

        private static int MethodConver(string method)

        {

            switch (method.ToUpper())

            {

                case "GET":

                    return 0;

                case "POST":

                    return 1;

                case "PUT":

                    return 2;

                case "DELETE":

                    return 3;

                default:

                    break;

            }

            return 0;

        }

        public static string ReadStream(Stream stream)

        {

            var content = string.Empty;

            if (stream != null)

            {

                stream.Seek(0, SeekOrigin.Begin);

                int len = (int)stream.Length;

                byte[] inputByts = new byte[len];

                stream.Read(inputByts, 0, len);

                stream.Position = 0;

                content = Encoding.UTF8.GetString(inputByts);

            }

            return content;

        }

    }

  public static class WebApiConfig

    {

        public static void Register(HttpConfiguration config)

        {

            // Web API configuration and services

            // Web API routes

            config.MapHttpAttributeRoutes();

            config.Filters.Add(new MonitorApiAttribute());

            config.Routes.MapHttpRoute(

                name: "DefaultApi",

                routeTemplate: "api/{controller}/{id}",

                defaults: new { id = RouteParameter.Optional }

            );

        }

    }