/// <summary>
        /// 按需要更新的构建者
        /// 递归构建Update操作串
        /// </summary>
        /// <param name="fieldList"></param>
        /// <param name="property"></param>
        /// <param name="propertyValue"></param>
        /// <param name="item"></param>
        /// <param name="fatherValue"></param>
        /// <param name="father"></param>
        private void GenerateRecursionExpress(
          List<UpdateDefinition<TEntity>> fieldList,
          PropertyInfo property,
          object propertyValue,
          TEntity item,
          object fatherValue,
          string father)
        {
            //复杂类型
            if (property.PropertyType.IsClass && property.PropertyType != typeof(string) && propertyValue != null)
            {
                //集合
                if (typeof(IList).IsAssignableFrom(propertyValue.GetType()))
                {
                    var modifyIndex = 0;//要更新的记录索引
                    foreach (var sub in property.PropertyType.GetProperties(BindingFlags.Instance | BindingFlags.Public))
                    {
                        if (sub.PropertyType.IsClass && sub.PropertyType != typeof(string))
                        {
                            var arr = propertyValue as IList;
                            if (arr != null && arr.Count > 0)
                            {

                                var oldValue = property.GetValue(fatherValue ?? item) as IList;
                                if (oldValue != null)
                                {
                                    for (int index = 0; index < arr.Count; index++)
                                    {
                                        for (modifyIndex = 0; modifyIndex < oldValue.Count; modifyIndex++)
                                            if (sub.PropertyType.GetProperty(EntityKey).GetValue(oldValue[modifyIndex]).ToString()
                                                == sub.PropertyType.GetProperty(EntityKey).GetValue(arr[index]).ToString())//比较_id是否相等
                                                break;
                                        foreach (var subInner in sub.PropertyType.GetProperties(BindingFlags.Instance | BindingFlags.Public))
                                        {
                                            if (string.IsNullOrWhiteSpace(father))
                                                GenerateRecursionExpress(fieldList, subInner, subInner.GetValue(arr[index]), item, arr[index], property.Name + "." + modifyIndex);
                                            else
                                                GenerateRecursionExpress(fieldList, subInner, subInner.GetValue(arr[index]), item, arr[index], father + "." + property.Name + "." + modifyIndex);
                                        }
                                    }
                                }

                            }
                        }
                    }
                }
                //实体
                else
                {
                    foreach (var sub in property.PropertyType.GetProperties(BindingFlags.Instance | BindingFlags.Public))
                    {

                        if (string.IsNullOrWhiteSpace(father))
                            GenerateRecursionExpress(fieldList, sub, sub.GetValue(propertyValue), item, property.GetValue(fatherValue), property.Name);
                        else
                            GenerateRecursionExpress(fieldList, sub, sub.GetValue(propertyValue), item, property.GetValue(fatherValue), father + "." + property.Name);
                    }
                }
            }
            //简单类型
            else
            {
                if (property.Name != EntityKey)//更新集中不能有实体键_id
                {
                    if (string.IsNullOrWhiteSpace(father))
                        fieldList.Add(Builders<TEntity>.Update.Set(property.Name, propertyValue));
                    else
                        fieldList.Add(Builders<TEntity>.Update.Set(father + "." + property.Name, propertyValue));
                }
            }
        }