我同意伊泰的观点。
也许这个代码示例可以帮助你。
制作映射到 db 表的实体。
public class EmailState
{
public int Id { get; private set; }
public List<AttachmentState> Resources { get; set; }
public static Email ToEmail(EmailState state)
{
return new Email(state);
}
}
public class AttachmentState
{
public static Attachment ToAttachment(AttachmentState state)
{
return new Attachment(state);
}
public Attachment ToAttachment()
{
return new Attachment(this);
}
}
制作可供用户使用的课程
public class Email
{
public Email()
{
this.State = new EmailState();
}
internal Email(EmailState state)
{
this.State = state;
}
internal EmailState State { get; set; }
public int Id { get; private set; }
public IEnumerable<Attachment> Attachments()
{
return this.State.Resources.Select(x => x.ToAttachment());
}
public void AddAttachment(Attachment attachment)
{
this.State.Resources.Add(attachment.State);
}
}
public class Attachment
{
public Attachment()
{
this.State = new AttachmentState();
}
internal Attachment(AttachmentState state)
{
this.State = state;
}
internal AttachmentState State { get; set; }
}
定义 DbContext
public class EmailDbContext : DbContext
{
public DbSet<EmailState> Emails { get; set; }
public DbSet<AttachmentState> Attachments { get; set; }
}
制作存储库
public interface IEmailRepository
{
void Add(Email email);
Email GetById(int emailId);
}
public class EmailRepository : IEmailRepository
{
private EmailDbContext _context;
public EmailRepository(EmailDbContext context)
{
_context = context;
}
public void Add(Email email)
{
_context.Emails.Add(email.State);
}
public Email GetById(int emailId)
{
EmailState emailState = _context.Emails.Single(x => x.Id == emailId);
return new Email(emailState);
}
}
像这样使用它
using (var context = new EmailDbContext())
{
IEmailRepository repository = new EmailRepository(context);
var email = new Email();
repository.Add(email);
context.SaveChanges();
var emailFoundById = repository.GetById(email.Id);
}