how to inject dependency in _viewimports file

Question

I am trying to generate a generic BaseViewPage in asp.net Core to access Current User's Identities.

For this purpose I created a BaseViewPage.cs file -

 public abstract class BaseViewPage<TModel> : RazorPage<TModel>
    {
        private static ClaimsPrincipal principal;
        public BaseViewPage(IPrincipal _principal)
        {
            principal = _principal as ClaimsPrincipal;
        }
    }

As you can see in the constructor here I am injecting a dependency of IPrincipal type so that it gets defined at run time.

Now time to inherit it in _viewimports.cshtml file to use current user in all the view pages as below -

@using TWCStore
@inherits MyStore.Helpers.BaseViewPage<TModel>
@addTagHelper *, Microsoft.AspNetCore.Mvc.TagHelpers

Whenever I try to use any property in my view - ProductCategories.cshtml the error invokes here

Severity Code Description Project File Line Suppression State Error CS7036 There is no argument given that corresponds to the required formal parameter '_principal' of 'BaseViewPage.BaseViewPage(IPrincipal)' MyStore D:\Projects\TWCStore\TWCStore\Views\Store\ProductCategories.cshtml 1 Active

I am assuming when I am injecting the dependency then it wants me to put the IPrincipal as Dependency here too -

 @inherits MyStore.Helpers.BaseViewPage<TModel>

How do I inject this dependency in here ?

Answer 1

Its late I am writing solution (actually an alternate) to this problem here.

So I followed dependency injection (sorry for now forgetting the help link).

Here is what I did -

Create an Interface

public interface IAppUserAccessor
    {
        int MemberId { get; }
    }

Resolver class

 public class AppUserAccessor : IAppUserAccessor
    {
        private readonly MyContext _context;
        public AppUserAccessor(MyContext context)
        {
            _context = context;
        }

        int IAppUserAccessor.MemberId
        {
            get
            {
                return _context.Member.MemberId;
            }
        }
    }

Register the service in StartUp.cs under 'ConfigureServices' section

 services.AddTransient<IAppUserAccessor, AppUserAccessor>();

Inject in _viewimports.cshtml

@using MyApplication
@inject MyApplication.Helpers.IAppUserAccessor AppUserAccessor

Now this is accessible in every view as -

@AppUserAccessor.MemberId