有没有办法用linq做到这一点而不用枚举fooCollection两次？varfooCollection=//getfoovarselectedIds=newList();varaggregateContent=String.Empty;foreach(varfinfoo){selectedIds.Add(foo.Id);aggregateContent+=foo.Content}varresults=newFooResults{Content=aggregateContent,SelectedIds=selectedIds};returnresults;