DI Setup using HostApplicationBuilder

DataAccess/EF_Demo/DISetup.cs

@@ -1,32 +1,27 @@
-using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
 using Microsoft.Extensions.Logging;
 
 namespace EF_Demo;
 
-internal class DISetup
+internal static class DISetup
 {
-  public static ServiceProvider BuildDI()
+  public static IHost BuildHost(string[] args)
   {
-    var configuration = new ConfigurationBuilder()
+    HostApplicationBuilder builder = Host.CreateApplicationBuilder(args);
-                            .AddJsonFile("appsettings.json")
-                            .AddUserSecrets<Program>()
-                            .Build();
 
-    IServiceCollection services = new ServiceCollection();
+    builder.Services.AddDbContextFactory<Data.Postgres.EventsContext>(options => {
+      options.UseNpgsql(builder.Configuration.GetConnectionString("EventsPostgres"));
+    });
+    builder.Services.AddDbContextFactory<Data.MSSQL.EventsContext>(options =>
+    {
+      options.UseSqlServer(builder.Configuration.GetConnectionString("EventsMssql"));
+    });
  
-    var provider = services.AddLogging(configure => {
+    builder.Services.AddTransient<Demo>();
-                              configure.AddConfiguration(configuration.GetSection("Logging"));
+
-                              configure.AddConsole();
+    return builder.Build();
-                            })
-                            .AddDbContext<Data.MSSQL.EventsContext>(options => {
-                              options.UseSqlServer(configuration.GetConnectionString("EventsMssql"));
-                            }, contextLifetime: ServiceLifetime.Transient)
-                            .AddDbContext<Data.Postgres.EventsContext>(options => {
-                               options.UseNpgsql(configuration.GetConnectionString("EventsPostgres"));
-                            }, contextLifetime: ServiceLifetime.Transient)
-                           .BuildServiceProvider();
-    return provider;
   }
 }

DataAccess/EF_Demo/Demo.cs

@@ -1,29 +1,28 @@
-#if POSTGRES
+#if POSTGRES
 using EF_Demo.Data.Postgres;
 #else
 using EF_Demo.Data.MSSQL;
 #endif
 
 using EF_Demo.Models;
-using Microsoft.Extensions.DependencyInjection;
+using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.Logging;
 
 namespace EF_Demo;
 
-internal class Demo
+internal class Demo(IDbContextFactory<EventsContext> contextFactory, ILogger<Demo> logger)
 {
-  internal static int? AddEvent(IServiceProvider serviceProvider, string eventName, DateOnly eventDate)
+  internal int? AddEvent(string eventName, DateOnly eventDate)
   {
-    ILogger logger = serviceProvider.GetRequiredService<ILogger<Demo>>();
     try
     {
-      using var ctx = serviceProvider.GetRequiredService<EventsContext>();
+      using var ctx = contextFactory.CreateDbContext();
       Event @event = new()
       {
         Name = eventName,
         EventDate = eventDate
       };
-      ctx.Add(@event);  //or ctx.Events.Add(@event) or ctx.Set<Event>().Add(@event);
+      ctx.Add(@event);
       ctx.SaveChanges();
       logger.LogInformation($"Event {eventName} successfully added with id {@event.Id}");
       return @event.Id;
@@ -35,16 +34,15 @@ internal class Demo
     }
   }
 
-  internal static void DeleteEvent(IServiceProvider serviceProvider, int eventId)
+  internal void DeleteEvent(int eventId)
   {
-    ILogger logger = serviceProvider.GetRequiredService<ILogger<Demo>>();
     try
     {
-      using var ctx = serviceProvider.GetRequiredService<EventsContext>();
+      using var ctx = contextFactory.CreateDbContext();
       Event? @event = ctx.Events.Find(eventId);
       if (@event != null)
       {
-        ctx.Remove(@event); //or ctx.Entry(product).State = EntityState.Deleted;
+        ctx.Remove(@event);
         ctx.SaveChanges();
         logger.LogInformation($"Event {@event.Name} deleted");
       }
@@ -59,12 +57,11 @@ internal class Demo
     }
   }
   
-  internal static void PostponeEvent(IServiceProvider serviceProvider, int eventId, int days)
+  internal void PostponeEvent(int eventId, int days)
   {
-    ILogger logger = serviceProvider.GetRequiredService<ILogger<Demo>>();
     try
     {
-      using var ctx = serviceProvider.GetRequiredService<EventsContext>();
+      using var ctx = contextFactory.CreateDbContext();
       Event? @event = ctx.Events.Find(eventId);
       if (@event != null)
       {
@@ -74,12 +71,12 @@ internal class Demo
       }
       else
       {
-        logger?.LogWarning($"Event #{eventId} does not exists");
+        logger.LogWarning($"Event #{eventId} does not exists");
       }
     }
     catch (Exception exc)
     {
-      logger?.LogError($"Error trying to change evenbt #{eventId}: {exc.CompleteExceptionMessage()}");
+      logger.LogError($"Error trying to change evenbt #{eventId}: {exc.CompleteExceptionMessage()}");
     }
   }
 
@@ -87,9 +84,9 @@ internal class Demo
   /// Print all people born in the provided year, ordered by country, and then by transliterated last name, and first name
   /// query is projected to an anonymous class
   /// </summary>
-  internal static void PrintPeople(IServiceProvider serviceProvider, int year)
+  internal void PrintPeople(int year)
   {
-    using var ctx = serviceProvider.GetRequiredService<EventsContext>();
+    using var ctx = contextFactory.CreateDbContext();
     var query = ctx.People
                    .Where(p => p.BirthDate.Year == year)
                    .OrderBy(p => p.CountryCodeNavigation.Name)

DataAccess/EF_Demo/EF_Demo.csproj

@@ -12,7 +12,7 @@
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">
-    <DefineConstants>$(DefineConstants);POSTGRES</DefineConstants>
+    <DefineConstants>$(DefineConstants);MSSQL</DefineConstants>
   </PropertyGroup>
 
   <ItemGroup>
@@ -21,7 +21,7 @@
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>
     <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="10.0.6" />
-    <PackageReference Include="Microsoft.Extensions.Configuration.UserSecrets" Version="10.0.6" />
+    <PackageReference Include="Microsoft.Extensions.Hosting" Version="10.0.6" />
     <PackageReference Include="Microsoft.Extensions.Logging.Console" Version="10.0.6" />
     <PackageReference Include="Npgsql.EntityFrameworkCore.PostgreSQL" Version="10.0.1" />
   </ItemGroup>

DataAccess/EF_Demo/Program.cs

@@ -1,21 +1,22 @@
-using EF_Demo;
+using EF_Demo;
 using Microsoft.Extensions.DependencyInjection;
 
 Console.OutputEncoding = System.Text.Encoding.UTF8;
 
-using ServiceProvider serviceProvider = DISetup.BuildDI();
+using var host = DISetup.BuildHost(args);
+Demo demo = host.Services.GetRequiredService<Demo>();
 
-Demo.PrintPeople(serviceProvider, 1976);
+demo.PrintPeople(1976);
 Util.EnterToContinue();
 
-int? eventId = Demo.AddEvent(serviceProvider, "Spring festival", new DateOnly(2026, 4, 30));
+int? eventId = demo.AddEvent("Spring festival", new DateOnly(2026, 4, 30));
 Util.EnterToContinue();
 
 if (eventId.HasValue)
 {
-  Demo.PostponeEvent(serviceProvider, eventId.Value, days: 5);
+  demo.PostponeEvent(eventId.Value, days: 5);
   Util.EnterToContinue();
 
-  Demo.DeleteEvent(serviceProvider, eventId.Value);
+  demo.DeleteEvent(eventId.Value);
   Util.EnterToContinue(clearConsole: false);
 }

DataAccess/EF_Demo/Properties/launchSettings.json

@@ -0,0 +1,10 @@
+{
+  "profiles": {
+    "DataGenerator": {
+      "commandName": "Project",
+      "environmentVariables": {
+        "DOTNET_ENVIRONMENT": "Development"
+      }
+    }
+  }
+}