How to trace each request ASP.NET Web API with NLog

That's what you have action filters for...to do something before/after an action method is a executing/executed

public class MyCustomFilter : System.Web.Http.Filters.ActionFilterAttribute{    public override void OnActionExecuting(HttpActionContext actionContext)    {        //Do something here before an action method starts executing    }    public override void OnActionExecuted(System.Web.Http.Filters.HttpActionExecutedContext context)    {        //Do something here after an action method finished executing    }}

Then, you'll need to plug this filter in the asp.net pipeline...when the application starts, whether you use owin/katana or global.asax it doesn't matter...

GlobalConfiguration.Configuration.Filters.Add(new MyCustomFilter());

The line above will add that filter to all action methods. If you want to turn tracing off for some action methods, simply add a flag/switch property to the action filter so that you can switch tracing off for some actions...

public class MyCustomFilter : System.Web.Http.Filters.ActionFilterAttribute{    public bool DisableTracing{get;set;}    public override void OnActionExecuting(HttpActionContext actionContext)    {        if(!DisableTracing){               //Do something here before an action method starts executing        }    }    public override void OnActionExecuted(System.Web.Http.Filters.HttpActionExecutedContext context)    {        if(!DisableTracing){               //Do something here before an action method starts executing        }    }}

And now you can turn it of on controller action...

[MyCustomFilter(DisableTracing = true)]public IHttpActionResult MyAction(int id){}

Update

To read the JSON object from the request's body simply read the content of the request as below...

 request.Content.ReadAsStringAsync().Result;

The solution of Leo seems correct for MVC but for Http REST API I had to implement the solution from http://www.c-sharpcorner.com/UploadFile/1492b1/restful-day-sharp6-request-logging-and-exception-handingloggin/

public class HttpLoggingFilterAttribute : System.Web.Http.Filters.ActionFilterAttribute{    public override void OnActionExecuting(System.Web.Http.Controllers.HttpActionContext filterContext)    {        //Do something here    }    public override void OnActionExecuted(System.Web.Http.Filters.HttpActionExecutedContext actionExecutedContext)    {        //Do something here    }}

After testing both method on my code I can tell the code from Leo is performed on an page refresh bit not on simple REST request.