kxs-admin/AppStart/TemplateViewLocationExpander.cs

using System;
using System.Collections.Generic;
using System.Linq;
using Microsoft.AspNetCore.Mvc.Razor;

namespace MySystem
{
    public class TemplateViewLocationExpander : IViewLocationExpander
    {
        public IEnumerable<string> ExpandViewLocations(ViewLocationExpanderContext context, IEnumerable<string> viewLocations)
        {
            string[] locations = {
                "/Areas/Admin/Views/BsServer/{1}/{0}.cshtml",
                "/Areas/Admin/Views/MainServer/{1}/{0}.cshtml",
                "/Areas/Admin/Views/JobServer/{1}/{0}.cshtml",
                "/Areas/Admin/Views/CashServer/{1}/{0}.cshtml",
                "/Areas/Admin/Views/SpServer/{1}/{0}.cshtml",
            };
            return locations.Union(viewLocations);
        }

        public void PopulateValues(ViewLocationExpanderContext context)
        {
            context.Values["template"] = context.ActionContext.RouteData.Values["Template"]?.ToString() ?? "Default";
        }
    }
}