[Web API] Custom http header in request or response

 ASP.NET    Web API  

▌Introduction

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How to receive custom http header from http request or append a new one on http response in ASP.NET Web API 2.

▌Environment

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▋Visual Studio 2017 community 15.3.3

▋ASP.NET Web API2

▌Implement

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▋In Action

▋Get custom http header’s value from http request

var headers = Request.Headers;

IEnumerable<string> values = null;

if (headers.TryGetValues("my-token", out values))

{

    var token = values.FirstOrDefault();

}

However, you can use this extension: Raz.HeaderAttribute, to get the custom header like this,

public async Task<Something> Get([FromHeader("my-token")] string token)

{

}

PS. This feature is available on ASP.NET Core now.

▋Append custom http header’s value to http response

// Create response

var response = Request.CreateResponse(HttpStatusCode.OK, myContent);

response.Headers.Add("my-token", "xxxxxxxxxxxx");

▋ActionFilter Attribute

Also we can implement an ActionFilterAttribute to apply the custom http header handling to actions.

public class MyFilterAttribute : ActionFilterAttribute

{

public override void OnActionExecuting(HttpActionContext actionContext)

        {

            // Current request headers

            var headers = actionContext.Request.Headers;

            IEnumerable<string> values = null;

            if (headers.TryGetValues("my-token", out values))

            {

                var token = values.FirstOrDefault();

                //Optional: Set the custom value to BaseController's public property

var baseController = actionContext.ControllerContext.Controller as BaseController;

if (baseController != null)

{

baseController.MyToken = token;

}

            }

        }

        public override void OnActionExecuted(HttpActionExecutedContext actionContext)

        {

            actionContext.Response.Headers.Add("my-token", "xxxxxxxxx");

        }

}

▌Reference

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