/// <summary>
        /// 同类型数据赋值
        /// </summary>
        /// <param name="DataSetter">需要设置值的对象</param>
        /// <param name="DataGetter">值来源</param> 
        /// <param name="IsLinqData">是否为linq模式</param>
        public static void SameValueCopier(object DataSetter, object DataGetter,bool IsLinqData)
        {

            PropertyInfo[] propertyInfoList = DataSetter.GetType().GetProperties();
            foreach (PropertyInfo propertyInfo in propertyInfoList)
            {
                if (propertyInfo.MemberType == MemberTypes.Property)
                {
                    string propertyName = propertyInfo.Name;
                    object value = DataGetter.GetType().GetProperty(propertyName).GetValue(DataGetter, null);
                    if (IsLinqData)
                    {
                        if (!propertyInfo.PropertyType.IsGenericType)
                        {  
                            DataSetter.GetType().GetProperty(propertyName).SetValue(DataSetter, value, null);
                        }
                    }
                    else
                    {  
                        DataSetter.GetType().GetProperty(propertyName).SetValue(DataSetter, value, null);
                    }
                    
                }
            }
        }


        /// <summary>
        /// 同类型数据赋值
        /// </summary>
        /// <param name="DataSetter">需要设置值的对象</param>
        /// <param name="DataGetter">值来源</param> 
        /// <param name="IsLinqData">是否为linq模式</param>
        public static void DiffValueCopier(object DataSetter, object DataGetter,bool IsLinqData)
        {

            PropertyInfo[] propertyInfoSetterList = DataSetter.GetType().GetProperties();
            PropertyInfo[] propertyInfoGetterList = DataGetter.GetType().GetProperties();

            foreach (PropertyInfo dataSetterPropertyInfo in propertyInfoSetterList)
            {
                if (dataSetterPropertyInfo.MemberType == MemberTypes.Property)
                {
                    string dataSetterPropertyName =  dataSetterPropertyInfo.Name;

                    foreach (PropertyInfo dataGetterPropertyInfo in propertyInfoGetterList)
                    {
                        string dataGetterPropertyName = dataGetterPropertyInfo.Name;
                        object value = DataGetter.GetType().GetProperty(dataGetterPropertyName).GetValue(DataGetter, null);
                        if (dataSetterPropertyName == dataGetterPropertyName)
                        {
                            if (IsLinqData)
                            {
                                if (!dataSetterPropertyInfo.PropertyType.IsGenericType)
                                {
                                    DataSetter.GetType().GetProperty(dataSetterPropertyName).SetValue(DataSetter, value, null);
                                    break;
                                }
                            }
                            else
                            {
                                DataSetter.GetType().GetProperty(dataSetterPropertyName).SetValue(DataSetter, value, null);
                                break;
                            }
                        }
                    } 
                }
            }
        }

            Category newc = new Category { ID = "1", P_ID = "0", Name = "b" };
            Category oldc = db.Category.Where(r => r.ID == "1").First();

            SameValueCopier(oldc, newc);
            db.SubmitChanges();
            kmdc.SubmitChanges();

SameValueCopier已测试通过