How to safely access actionContext.Request.Headers.GetValues if the key is not found?

Question

I am currently doing this, but it throws an exception if the key is not found.

This snippet is inside of a web api filter that inherits from ActionFilterAttribute, in the overriden method OnActionExecuting.

if (actionContext.Request.Headers.GetValues("some_key") != null                  && actionContext.Request.Headers.GetValues("some_key").First() == "hello") {  } 

Am I forced to wrap this in a try/catch?

Answer 1

class MyFilter : System.Web.Http.Filters.ActionFilterAttribute {     public override void OnActionExecuting(System.Web.Http.Controllers.HttpActionContext actionContext)     {         IEnumerable<string> values;         if (actionContext.Request.Headers.TryGetValues("some_key", out values) && values.First() == "hello")         {          }     } } 

Answer 2

Since the release of C# 6.0, here is an alternative syntax to Yuriy Faktorovich's answer where you will get the header value or null as a result in a single line.

actionContext.Request.Headers.SingleOrDefault(x => x.Key == "some_key").Value?.First()