我也是才开始接触的,我描述的也不是很清楚，不知道大神们能不能理解的意思！！

 public class DBContextFactory
    {
       public static DbContext GetCurrentContext()
       {
           //CallContext:保证线程内创建的数据操作上下文是唯一的。
           DbContext DbContext = (DbContext)CallContext.GetData("context");
           if (DbContext == null)
           {
               DbContext = new EFBaseDbContext();
               CallContext.SetData("context", DbContext);
           }
           return DbContext;
       }
    }

//EFBaseDbContext

    public class EFBaseDbContext : DbContext
    {
        public EFBaseDbContext()
            : base("SQLConn.Traffic")
        {
        }

        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            //base.OnModelCreating(modelBuilder);
            Database.SetInitializer<EFBaseDbContext>(null);
            modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();
        }

        public DbSet<User_Info> Users { get; set; }
    }

//DAL 获取当前上下文
        public DbContext context = DBContextFactory.GetCurrentContext();