#region List <=> DataTable 互相转换        /// 
         /// LINQ返回DataTable类型        /// 
         /// 
         
                 ///           /// 
         
                 public static DataTable ListToDataTable
        
         (IEnumerable
         
           varlist)        {            DataTable dtReturn = new DataTable();            // column names             PropertyInfo[] oProps = null;            if (varlist == null)                return dtReturn;            foreach (T rec in varlist)            {                if (oProps == null)                {                    oProps = ((Type)rec.GetType()).GetProperties();                    foreach (PropertyInfo pi in oProps)                    {                        Type colType = pi.PropertyType;                        if ((colType.IsGenericType) && (colType.GetGenericTypeDefinition()                             == typeof(Nullable<>)))                        {                            colType = colType.GetGenericArguments()[0];                        }                        dtReturn.Columns.Add(new DataColumn(pi.Name, colType));                    }                }                DataRow dr = dtReturn.NewRow();                foreach (PropertyInfo pi in oProps)                {                    dr[pi.Name] = pi.GetValue(rec, null) == null ? DBNull.Value : pi.GetValue                    (rec, null);                }                dtReturn.Rows.Add(dr);            }            return dtReturn;        }