Audit z Entity Framework Plus

DataContext1.cs

public class DataContext : DbContext
{
    public DataContext()
        : base("Name=DefaultConnection")
    {
        
    }

    public DbSet<Category> Categories { get; set; }

    public DbSet<Product> Products { get; set; }
}

DataContext2.cs

public class DataContext : DbContext
{
    static DataContext()
    {
        AuditManager.DefaultConfiguration.AutoSavePreAction = (context, audit) =>
           (context as DataContext).AuditEntries.AddRange(audit.Entries);
    }

    public DataContext()
        : base("Name=DefaultConnection")
    {
        
    }

    public DbSet<Category> Categories { get; set; }

    public DbSet<Product> Products { get; set; }

    public DbSet<AuditEntry> AuditEntries { get; set; }

    public DbSet<AuditEntryProperty> AuditEntryProperties { get; set; }

}

DataContext3.cs

public class DataContext : DbContext
{
    static DataContext()
    {
        AuditManager.DefaultConfiguration.AutoSavePreAction = (context, audit) =>
           (context as DataContext).AuditEntries.AddRange(audit.Entries);
    }

    public DataContext()
        : base("Name=DefaultConnection")
    {
        
    }

    public DbSet<Category> Categories { get; set; }

    public DbSet<Product> Products { get; set; }

    public DbSet<AuditEntry> AuditEntries { get; set; }

    public DbSet<AuditEntryProperty> AuditEntryProperties { get; set; }

    public string UserName { get; set; } = "System";

    public override int SaveChanges()
    {
        var audit = new Audit();
        audit.CreatedBy = UserName;

        audit.PreSaveChanges(this);
        var rowAffecteds = base.SaveChanges();
        audit.PostSaveChanges();

        if (audit.Configuration.AutoSavePreAction != null)
        {
            audit.Configuration.AutoSavePreAction(this, audit);
            base.SaveChanges();
        }

        return rowAffecteds;
    }
}

Models.cs

public class BaseModel
{
    public BaseModel()
    {
        IsActive = true;
    }

    public int Id { get; set; }

    public bool IsActive { get; set; }
}

public class Category : BaseModel
{
    public string Name { get; set; }

    public virtual ICollection<Product> Products { get; set; }
}

public class Product : BaseModel
{
    public string Name { get; set; }

    public int CategoryId { get; set; }

    public virtual Category Category { get; set; }
}

Program1.cs

class Program
{
    static void Main(string[] args)
    {
        int id = AddTest();
        EditTest();
        DeleteTest();
    }

    static int AddTest()
    {
        using (DataContext db = new DataContext())
        {
            var category = db.Categories.FirstOrDefault();

            var product = new Product()
            {
                Name = "Product Name",
                Category = category
            };

            db.Products.Add(product);

            db.SaveChanges();

            return product.Id;
        }
    }

    static void EditTest()
    {
        using (DataContext db = new DataContext())
        {
            var category = db.Categories
                .OrderByDescending(c => c.Id)
                .FirstOrDefault();

            var product = db.Products
                .OrderByDescending(c => c.Id)
                .FirstOrDefault();

            product.Category = category;
            product.Name = "New Product Name";

            db.SaveChanges();
        }
    }

    static void DeleteTest()
    {
        using (DataContext db = new DataContext())
        {
            var product = db.Products
                .OrderByDescending(c => c.Id)
                .FirstOrDefault();

            db.Products.Remove(product);

            db.SaveChanges();
        }
    }
}

Program2.cs

static int AddTest()
{
    using (DataContext db = new DataContext())
    {
        var category = db.Categories.FirstOrDefault();

        var product = new Product()
        {
            Name = "Product Name",
            Category = category
        };

        db.Products.Add(product);

        var audit = new Audit();
        audit.CreatedBy = "UserName";
        db.SaveChanges(audit);

        return product.Id;
    }
}

Program3.cs

static void ShowHistory(int id)
{
    using (DataContext db = new DataContext())
    {
        var histories = db.AuditEntries.Where<Product>(id);

        foreach (var history in histories)
        {
            Console.WriteLine($"State: {history.State}");

            foreach (var property in history.Properties)
            {
                Console.WriteLine($"Propepty: {property.PropertyName}, OldValue: {property.OldValue}, NewValue: {property.NewValue}");
            }

            Console.WriteLine();
        }
    }
}