LinQ：list基础操作

1、list去重分组：

List<TcmClinicatWCFService.TCM_SYMPTOMS> listSymptoms = (from a in list
                                                         group a by new { a.CODE, a.ISO_NAME } into grouping
                                                         select new TcmClinicatWCFService.TCM_SYMPTOMS
                                                         {
                                                             CODE = grouping.Key.CODE,
                                                             ISO_NAME = grouping.Key.ISO_NAME
                                                         }).ToList();

2、list取随机：

            Random rd = new Random();

            List<string> liststr = new List<string>();
            liststr.Add("aaa");
            liststr.Add("bbb");
            liststr.Add("ccc");
            liststr.Add("111");
            liststr.Add("222");
            liststr.Add("333");
            //随机一个
            var s = liststr.OrderBy(_ => Guid.NewGuid()).First();
            //随机两个
            var ss = liststr.OrderBy(_ => Guid.NewGuid()).Take(2);
            //乱序
            var sss = liststr.OrderBy(o => rd.Next(0, liststr.Count())).ToList();