/// <summary>
        /// DataTable 转换为List 集合
        /// </summary>
        /// <typeparam name="TResult">类型</typeparam>
        /// <param name="dt">DataTable</param>
        /// <returns></returns>
        public static List<T> ToList<T>(this DataTable dt) where T : class,new()
        {
            //创建一个属性的列表
            List<PropertyInfo> prlist = new List<PropertyInfo>();
            //获取TResult的类型实例  反射的入口
            Type t = typeof(T);
            //获得TResult 的所有的Public 属性 并找出TResult属性和DataTable的列名称相同的属性(PropertyInfo) 并加入到属性列表 
            Array.ForEach<PropertyInfo>(t.GetProperties(), p => { if (dt.Columns.IndexOf(p.Name) != -1) prlist.Add(p); });
            //创建返回的集合
            List<T> oblist = new List<T>();
            foreach (DataRow row in dt.Rows)
            {
                //创建TResult的实例
                T ob = new T();
                //找到对应的数据  并赋值
                //prlist.ForEach(p => { if (row[p.Name] != DBNull.Value) p.SetValue(ob, row[p.Name], null); });
                prlist.ForEach(p =>
                {
                    if (row[p.Name] != DBNull.Value)
                    {
                            p.SetValue(ob, row[p.Name], null);
                    }
                    else
                    {
                        if (p.PropertyType == typeof(string))
                        {
                            p.SetValue(ob, string.Empty, null);
                        }
                    }

                });
                //放入到返回的集合中.
                oblist.Add(ob);
            }
            return oblist;
        }

public static class ListExtension
    {
        public static DataTable ListConvertDataTable<T>(List<T> model, string TableName) where T : class
        {
            try
            {
                Type value = typeof(T);
                List<PropertyInfo> list = new List<PropertyInfo>(value.GetProperties()); //属性列表
                DataTable table = new DataTable();//实例化datatable
                table.TableName = TableName; //表名
                foreach (var property in list)
                {
                    //获取属性数据类型
                    Type PropertyType = property.PropertyType;
                    //验证数据类型是否为空
                    if (PropertyType.IsGenericType && PropertyType.GetGenericTypeDefinition() == typeof(Nullable<>))
                    {
                        PropertyType = property.PropertyType.GetGenericArguments()[0];
                    }
                    table.Columns.Add(property.Name, PropertyType);
                }
                foreach (var dataValue in model)
                {
                    DataRow row = table.NewRow();
                    list.ForEach(p => { row[p.Name] = p.GetValue(dataValue); });
                    table.Rows.Add(row);
                }
                return table;
            }
            catch (Exception ex)
            {
                return null;
            }
        }
    }

        /// <summary>
        /// DataRow 转换成 Model
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="dr"></param>
        /// <returns></returns>
        public static T ConvertToModel<T>(this System.Data.DataRow dr) where T : new()
        {
            T model = new T();
            foreach (PropertyInfo pInfo in model.GetType().GetProperties())
            {
                object val = getValueByColumnName(dr, pInfo.Name);
                pInfo.SetValue(model, val, null);
            }
            return model;
        }
        /// <summary>
        /// 获取该列的值
        /// </summary>
        /// <param name="dr"></param>
        /// <param name="columnName"></param>
        /// <returns></returns>
        public static object getValueByColumnName(System.Data.DataRow dr, string columnName)
        {
            if (dr.Table.Columns.IndexOf(columnName) >= 0)
            {
                if (dr[columnName] == DBNull.Value)
                {
                    return null;
                }
                return dr[columnName];
            }
            return null;
        }