Refactored.

src/Volo.Abp.EntityFrameworkCore/Volo/Abp/Uow/EntityFrameworkCore/DbContextEfCoreTransactionStrategy.cs

@@ -1,46 +0,0 @@
-using System.Data;
-using Microsoft.EntityFrameworkCore;
-using Microsoft.EntityFrameworkCore.Storage;
-using Microsoft.Extensions.DependencyInjection;
-using Volo.Abp.DependencyInjection;
-using Volo.Abp.EntityFrameworkCore;
-using Volo.Abp.EntityFrameworkCore.DependencyInjection;
-
-namespace Volo.Abp.Uow.EntityFrameworkCore
-{
-    public class DbContextEfCoreTransactionStrategy : IEfCoreTransactionStrategy, ITransientDependency
-    {
-        public TDbContext CreateDbContext<TDbContext>(IUnitOfWork unitOfWork, DbContextCreationContext creationContext) where TDbContext : DbContext
-        {
-            var transactionApiKey = $"EntityFrameworkCore_{creationContext.ConnectionString}";
-            var activeTransaction = unitOfWork.FindTransactionApi(transactionApiKey) as IEfCoreTransactionApi;
-
-            TDbContext dbContext;
-            if (activeTransaction == null)
-            {
-                dbContext = unitOfWork.ServiceProvider.GetRequiredService<TDbContext>();
-                var dbtransaction = dbContext.Database.BeginTransaction((unitOfWork.Options.IsolationLevel ?? IsolationLevel.ReadUncommitted));
-                activeTransaction = new EfCoreTransactionApi(dbtransaction, dbContext);
-                unitOfWork.AddTransactionApi(transactionApiKey, activeTransaction);
-            }
-            else
-            {
-                creationContext.ExistingConnection = activeTransaction.DbContextTransaction.GetDbTransaction().Connection;
-                dbContext = unitOfWork.ServiceProvider.GetRequiredService<TDbContext>();
-                
-                if (dbContext.HasRelationalTransactionManager())
-                {
-                    dbContext.Database.UseTransaction(activeTransaction.DbContextTransaction.GetDbTransaction());
-                }
-                else
-                {
-                    dbContext.Database.BeginTransaction();
-                }
-
-                activeTransaction.AttendedDbContexts.Add(dbContext);
-            }
-
-            return dbContext;
-        }
-    }
-}

src/Volo.Abp.EntityFrameworkCore/Volo/Abp/Uow/EntityFrameworkCore/DbContextDatabaseApi.cs → src/Volo.Abp.EntityFrameworkCore/Volo/Abp/Uow/EntityFrameworkCore/EfCoreDatabaseApi.cs

@@ -4,12 +4,12 @@ using Volo.Abp.EntityFrameworkCore;
 
 namespace Volo.Abp.Uow.EntityFrameworkCore
 {
-    public class DbContextDatabaseApi<TDbContext> : IDatabaseApi, ISupportsSavingChanges
+    public class EfCoreDatabaseApi<TDbContext> : IDatabaseApi, ISupportsSavingChanges
         where TDbContext : AbpDbContext<TDbContext>
     {
         public TDbContext DbContext { get; }
 
-        public DbContextDatabaseApi(TDbContext dbContext)
+        public EfCoreDatabaseApi(TDbContext dbContext)
         {
             DbContext = dbContext;
         }

src/Volo.Abp.EntityFrameworkCore/Volo/Abp/Uow/EntityFrameworkCore/EfCoreTransactionApi.cs

@@ -6,7 +6,7 @@ using Volo.Abp.EntityFrameworkCore;
 
 namespace Volo.Abp.Uow.EntityFrameworkCore
 {
-    public class EfCoreTransactionApi : IEfCoreTransactionApi
+    public class EfCoreTransactionApi : ITransactionApi
     {
         public IDbContextTransaction DbContextTransaction { get; }
         public DbContext StarterDbContext { get; }

src/Volo.Abp.EntityFrameworkCore/Volo/Abp/Uow/EntityFrameworkCore/IEfCoreTransactionApi.cs

@@ -1,15 +0,0 @@
-using System.Collections.Generic;
-using Microsoft.EntityFrameworkCore;
-using Microsoft.EntityFrameworkCore.Storage;
-
-namespace Volo.Abp.Uow.EntityFrameworkCore
-{
-    public interface IEfCoreTransactionApi : ITransactionApi
-    {
-        IDbContextTransaction DbContextTransaction { get; }
-
-        DbContext StarterDbContext { get; }
-
-        List<DbContext> AttendedDbContexts { get; }
-    }
-}

src/Volo.Abp.EntityFrameworkCore/Volo/Abp/Uow/EntityFrameworkCore/IEfCoreTransactionStrategy.cs

@@ -1,11 +0,0 @@
-using Microsoft.EntityFrameworkCore;
-using Volo.Abp.EntityFrameworkCore.DependencyInjection;
-
-namespace Volo.Abp.Uow.EntityFrameworkCore
-{
-    public interface IEfCoreTransactionStrategy
-    {
-        TDbContext CreateDbContext<TDbContext>(IUnitOfWork unitOfWork, DbContextCreationContext creationContext)
-            where TDbContext : DbContext;
-    }
-}

src/Volo.Abp.EntityFrameworkCore/Volo/Abp/Uow/EntityFrameworkCore/UnitOfWorkDbContextProvider.cs

@@ -1,5 +1,6 @@
 using System;
 using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Storage;
 using Microsoft.Extensions.DependencyInjection;
 using Volo.Abp.Data;
 using Volo.Abp.EntityFrameworkCore;
@@ -14,16 +15,13 @@ namespace Volo.Abp.Uow.EntityFrameworkCore
     {
         private readonly IUnitOfWorkManager _unitOfWorkManager;
         private readonly IConnectionStringResolver _connectionStringResolver;
-        private readonly IEfCoreTransactionStrategy _transactionStrategy;
 
         public UnitOfWorkDbContextProvider(
             IUnitOfWorkManager unitOfWorkManager,
-            IConnectionStringResolver connectionStringResolver,
-            IEfCoreTransactionStrategy transactionStrategy)
+            IConnectionStringResolver connectionStringResolver)
         {
             _unitOfWorkManager = unitOfWorkManager;
             _connectionStringResolver = connectionStringResolver;
-            _transactionStrategy = transactionStrategy;
         }
 
         public TDbContext GetDbContext()
@@ -41,11 +39,11 @@ namespace Volo.Abp.Uow.EntityFrameworkCore
 
             var databaseApi = unitOfWork.GetOrAddDatabaseApi(
                 dbContextKey,
-                () => new DbContextDatabaseApi<TDbContext>(
+                () => new EfCoreDatabaseApi<TDbContext>(
                     CreateDbContext(unitOfWork, connectionStringName, connectionString)
                 ));
 
-            return ((DbContextDatabaseApi<TDbContext>)databaseApi).DbContext;
+            return ((EfCoreDatabaseApi<TDbContext>)databaseApi).DbContext;
         }
 
         private TDbContext CreateDbContext(IUnitOfWork unitOfWork, string connectionStringName, string connectionString)
@@ -53,16 +51,7 @@ namespace Volo.Abp.Uow.EntityFrameworkCore
             var creationContext = new DbContextCreationContext(connectionStringName, connectionString);
             using (DbContextCreationContext.Use(creationContext))
             {
-                TDbContext dbContext;
-
-                if (unitOfWork.Options.IsTransactional == true)
-                {
-                    dbContext = _transactionStrategy.CreateDbContext<TDbContext>(unitOfWork, creationContext);
-                }
-                else
-                {
-                    dbContext = unitOfWork.ServiceProvider.GetRequiredService<TDbContext>();
-                }
+                var dbContext = CreateDbContext(unitOfWork);
 
                 if (unitOfWork.Options.Timeout.HasValue &&
                     dbContext.Database.IsRelational() &&
@@ -74,5 +63,56 @@ namespace Volo.Abp.Uow.EntityFrameworkCore
                 return dbContext;
             }
         }
+
+        private TDbContext CreateDbContext(IUnitOfWork unitOfWork)
+        {
+            return unitOfWork.Options.IsTransactional
+                ? CreateDbContextWithTransaction(unitOfWork)
+                : unitOfWork.ServiceProvider.GetRequiredService<TDbContext>();
+        }
+
+        public TDbContext CreateDbContextWithTransaction(IUnitOfWork unitOfWork) 
+        {
+            var transactionApiKey = $"EntityFrameworkCore_{DbContextCreationContext.Current.ConnectionString}";
+            var activeTransaction = unitOfWork.FindTransactionApi(transactionApiKey) as EfCoreTransactionApi;
+
+            if (activeTransaction == null)
+            {
+                var dbContext = unitOfWork.ServiceProvider.GetRequiredService<TDbContext>();
+
+                var dbtransaction = unitOfWork.Options.IsolationLevel.HasValue
+                    ? dbContext.Database.BeginTransaction(unitOfWork.Options.IsolationLevel.Value)
+                    : dbContext.Database.BeginTransaction();
+
+                unitOfWork.AddTransactionApi(
+                    transactionApiKey,
+                    new EfCoreTransactionApi(
+                        dbtransaction,
+                        dbContext
+                    )
+                );
+
+                return dbContext;
+            }
+            else
+            {
+                DbContextCreationContext.Current.ExistingConnection = activeTransaction.DbContextTransaction.GetDbTransaction().Connection;
+
+                var dbContext = unitOfWork.ServiceProvider.GetRequiredService<TDbContext>();
+
+                if (dbContext.HasRelationalTransactionManager())
+                {
+                    dbContext.Database.UseTransaction(activeTransaction.DbContextTransaction.GetDbTransaction());
+                }
+                else
+                {
+                    dbContext.Database.BeginTransaction(); //TODO: Why not using the new created transaction?
+                }
+
+                activeTransaction.AttendedDbContexts.Add(dbContext);
+
+                return dbContext;
+            }
+        }
     }
 }