通过反射向将EF的实体映射配置加入到实体模型中

        public AdminDbContext()
            : base("MemberDbContext")
        {
            //不使用代理创建导航属性，避免WCF序列化错误    
            Configuration.ProxyCreationEnabled = false;
            //Configuration.LazyLoadingEnabled = false;

        }
        public DbSet<Employee> Employees { get; set; }
        public DbSet<Role> Roles { get; set; }

        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();

            modelBuilder.Configurations.Add(new EmployeeMap());
            modelBuilder.Configurations.Add(new RoleMap());
            base.OnModelCreating(modelBuilder);
        }

        public int Commit()
        {
            return base.SaveChanges();
        }

    public class EmployeeMap : EntityTypeConfiguration<Employee>
    {
        ......
    }

        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            var typesToRegister = Assembly.GetExecutingAssembly().GetTypes()
            .Where(type => !String.IsNullOrEmpty(type.Namespace))
            .Where(type => type.BaseType != null && type.BaseType.IsGenericType && type.BaseType.GetGenericTypeDefinition() == typeof(EntityTypeConfiguration<>));
            foreach (var type in typesToRegister)
            {
                dynamic configurationInstance = Activator.CreateInstance(type);
                modelBuilder.Configurations.Add(configurationInstance);
            }
            //...or do it manually below. For example,
            //modelBuilder.Configurations.Add(new LanguageMap());

            base.OnModelCreating(modelBuilder);
        }