摘要：
一、构造3个对象的集合 List<VAV_AREA> arealist = new List<VAV_AREA>(); List<VAV_CORP> corplist = new List<VAV_CORP>(); List<VAV_CITY> citylist = new List<VAV_CITY>();二、得到集合数据三、linq处理2个list to linq left join var v = from area in arealist join corp in corplist.DefaultIfEmpty() 阅读全文
