Update views.md (dotnet#3203)

Andrew Germann · Rick Anderson · commit 862fb8a1f025 · 2017-04-11T08:42:56.000-10:00
* Update views.md

Just adding the using directive for the AuthorizationService injection.

* Update views.md
diff --git a/aspnetcore/security/authorization/views.md b/aspnetcore/security/authorization/views.md
@@ -16,7 +16,7 @@ uid: security/authorization/views
 
 <a name=security-authorization-views></a>
 
-Often a developer will want to show, hide or otherwise modify a UI based on the current user identity. You can access the authorization service within MVC views via [dependency injection](../../fundamentals/dependency-injection.md#fundamentals-dependency-injection). To inject the authorization service into a Razor view use the `@inject` directive, for example `@inject IAuthorizationService AuthorizationService`. If you want the authorization service in every view then place the `@inject` directive into the `_ViewImports.cshtml` file in the `Views` directory. For more information on dependency injection into views see [Dependency injection into views](../../mvc/views/dependency-injection.md).
+Often a developer will want to show, hide or otherwise modify a UI based on the current user identity. You can access the authorization service within MVC views via [dependency injection](../../fundamentals/dependency-injection.md#fundamentals-dependency-injection). To inject the authorization service into a Razor view use the `@inject` directive, for example `@inject IAuthorizationService AuthorizationService` (requires `@using Microsoft.AspNetCore.Authorization`). If you want the authorization service in every view then place the `@inject` directive into the `_ViewImports.cshtml` file in the `Views` directory. For more information on dependency injection into views see [Dependency injection into views](../../mvc/views/dependency-injection.md).
 
 Once you have injected the authorization service you use it by calling the `AuthorizeAsync` method in exactly the same way as you would check during [resource based authorization](resourcebased.md#security-authorization-resource-based-imperative).
 
