.net – 如何根据列表成员的属性拆分通用List(T)？

//if PropertyA is not int,change int to whatever that type is
Dictionary<int,List<foo>> myCollections =
  new Dictionary<int,List<foo>>();
//
foreach(Foo myFoo in fooList)
{
  //if I haven't seen this key before,make a new entry
  if (!myCollections.ContainsKey(myFoo.PropertyA))
  {
    myCollections.Add(myFoo.PropertyA,new List<foo>());
  }
  //now add the value to the entry.
  myCollections[myFoo.PropertyA].Add(myFoo);
}
//
// now recollect these lists into the result.
List<List<Foo>> result = new List<List<Foo>>();
foreach(List<Foo> someFoos in myCollections.Values)
{
  result.Add(someFoos);
}

如今,我只写：

List<List<foo>> result = fooList
  .GroupBy(foo => foo.PropertyA)
  .Select(g => g.ToList())
  .ToList();

要么

ILookup<TypeOfPropertyA,foo>> result = fooList.ToLookup(foo => foo.PropertyA);