object转List<XXX>的问题

List<object> demo(object a)
{
  List<object> res = new List<object>();
  object c = a;
  Type d = a.GetType();
  if (d is IList && d.IsGenericType)
  {
     IList list = (IList)c;
     res = (List<object>)list;     //这里可能会有问题，请自行修改，或者用 IList.Cast<object>() 进行转换
  }
  else
  {
     throw new Exception("parm is not my type")
  }
  return res;
}