protected void Application_Start()
{
  //增加Filter
  FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
  FilterConfig.RegisterApiFilters(GlobalConfiguration.Configuration.Filters);
}

public class FilterConfig
{
    public static void RegisterGlobalFilters(GlobalFilterCollection filters)
    {
        filters.Add(new HandleErrorAttribute());
    }
    public static void RegisterApiFilters(HttpFilterCollection filters)
    {
        filters.Add(new ApiAciontFilter());
    }
}
public class ApiAciontFilter : System.Web.Http.Filters.ActionFilterAttribute
{
    private const string Key = "__action_duration__";
    public override void OnActionExecuting(HttpActionContext actionContext)
    { 
        var stopWatch = new Stopwatch();
        actionContext.Request.Properties[Key] = stopWatch;
        stopWatch.Start();
    }
    public override void OnActionExecuted(HttpActionExecutedContext filterContext)
    {
        try
        {
            if (!filterContext.Request.Properties.ContainsKey(Key))
            {
                return;
            }
            var stopWatch = filterContext.Request.Properties[Key] as Stopwatch;
            if (stopWatch != null)
            {
                stopWatch.Stop();
                var clientIp = GetIPAddress(filterContext.Request);
                string msg = string.Format("{0}, {1}, {2}, {3} MS", clientIp, filterContext.Response.StatusCode, filterContext.Request.RequestUri.AbsolutePath, stopWatch.ElapsedMilliseconds);
                NLog.LogManager.GetCurrentClassLogger().Trace(msg); //正常日志输出 
            }
        }
        catch (Exception e)
        {
            NLog.LogManager.GetCurrentClassLogger().Error(e, e.Message);
        }
    }
    public static string GetIPAddress(HttpRequestMessage request)
    {
        string ip = "";
        try
        {
            if (request.Properties.ContainsKey("MS_HttpContext"))
            {
                ip = ((HttpContextWrapper)request.Properties["MS_HttpContext"]).Request.UserHostAddress;
            }
        }
        catch (Exception ex)
        {
        }
        if (ip == "::1") ip = "127.0.0.1";
        return ip;
    }
}