webformdependencyinjection_msdi

Global.asax.cs

using System;
using System.Web;

namespace Microsoft.Extensions.DependencyInjection.WebForms.Sample
{
    public class Global : HttpApplication
    {
        protected void Application_Start(object sender, EventArgs e)
        { 
            var collection = new ServiceCollection();
            collection.AddScoped<IDependency, Dependency>();
            var provider = new ServiceProvider(collection.BuildServiceProvider());
            HttpRuntime.WebObjectActivator = provider;
        }
    }
}

ServiceProvider.cs

using System;
using System.Reflection;
using System.Web;

namespace Microsoft.Extensions.DependencyInjection.WebForms
{
    public class ServiceProvider : IServiceProvider
    {
        private readonly IServiceProvider _serviceProvider;

        public ServiceProvider(IServiceProvider serviceProvider)
        {
            _serviceProvider = serviceProvider;
        }

        public object GetService(Type serviceType)
        {
            try
            {
                IServiceScope lifetimeScope;
                var currentHttpContext = HttpContext.Current;
                if (currentHttpContext != null)
                {
                    lifetimeScope = (IServiceScope)currentHttpContext.Items[typeof(IServiceScope)];
                    if (lifetimeScope == null)
                    {
                        void CleanScope(object sender, EventArgs args)
                        {
                            if (sender is HttpApplication application)
                            {
                                application.RequestCompleted -= CleanScope;
                                lifetimeScope.Dispose();
                            }
                        }

                        lifetimeScope = _serviceProvider.CreateScope();
                        currentHttpContext.Items.Add(typeof(IServiceScope), lifetimeScope);
                        currentHttpContext.ApplicationInstance.RequestCompleted += CleanScope;
                    }
                }
                else
                {
                    lifetimeScope = _serviceProvider.CreateScope();
                }

                return ActivatorUtilities.GetServiceOrCreateInstance(lifetimeScope.ServiceProvider, serviceType);
            }
            catch (InvalidOperationException)
            {
                //No public ctor available, revert to a private/internal one
                return Activator.CreateInstance(serviceType, BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.CreateInstance, null, null, null);
            }
        }
    }
}