Startup.cs

using System;
using System.IO;
using System.Reflection;
using System.Runtime.InteropServices;
using DevExpress.AspNetCore;
using DevExpress.AspNetCore.Reporting;
using DevExpress.Security.Resources;
using DevExpress.Utils;
using DevExpress.XtraReports.Web.Extensions;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using ReportingWebApp.Data;
using ReportingWebApp.Services;

namespace ReportingWebApp {
    public class Startup {
        public Startup(IConfiguration configuration, IWebHostEnvironment environment) {
            Configuration = configuration;
            AppDomain.CurrentDomain.SetData("DataDirectory", environment.ContentRootPath);
        }

        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services) {
            services.AddDevExpressControls();
            services.AddScoped<ReportStorageWebExtension, CustomReportStorageWebExtension>();
            DeserializationSettings.RegisterTrustedClass(typeof(ReportingWebApp.Employees.DataSource));
            services
                .AddMvc()
                .AddNewtonsoftJson();
            services.ConfigureReportingServices(configurator => {
                configurator.ConfigureReportDesigner(designerConfigurator => {
                    designerConfigurator.RegisterDataSourceWizardConnectionStringsProvider<CustomSqlDataSourceWizardConnectionStringsProvider>();
                    designerConfigurator.RegisterDataSourceWizardJsonConnectionStorage<CustomDataSourceWizardJsonDataConnectionStorage>(true);
                    designerConfigurator.RegisterObjectDataSourceWizardTypeProvider<ObjectDataSourceWizardCustomTypeProvider>();
                });
                configurator.ConfigureWebDocumentViewer(viewerConfigurator => {
                    viewerConfigurator.UseCachedReportSourceBuilder();
                    viewerConfigurator.RegisterJsonDataConnectionProviderFactory<CustomJsonDataConnectionProviderFactory>();
                    viewerConfigurator.RegisterConnectionProviderFactory<CustomSqlDataConnectionProviderFactory>();
                });
                configurator.UseAsyncEngine();
            });

            services.AddDbContext<ReportDbContext>(options => options.UseSqlite(Configuration.GetConnectionString("ReportsDataConnectionString")));
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IWebHostEnvironment env, ReportDbContext db) {
            db.InitializeDatabase();
            app.UseDevExpressControls();

            var rootPath = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
            var dataDirectoryAllowRule = DirectoryAccessRule.Allow(new DirectoryInfo(Path.Combine(rootPath, "Data")).FullName);
            AccessSettings.DataResources.TrySetRules(dataDirectoryAllowRule, UrlAccessRule.Allow());
            System.Net.ServicePointManager.SecurityProtocol |= System.Net.SecurityProtocolType.Tls12;

            if(env.IsDevelopment()) {
                app.UseDeveloperExceptionPage();
            } else {
                app.UseExceptionHandler("/Home/Error");
                // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
                app.UseHsts();
            }
            app.UseHttpsRedirection();
            app.UseStaticFiles();

            app.UseRouting();

            app.UseAuthorization();
            app.UseEndpoints(endpoints => {
                endpoints.MapControllerRoute(
                    name: "default",
                    pattern: "{controller=Home}/{action=Index}/{id?}");
            });
        }
    }
}