可以添加Key 值相同的的集合或字典
var NeedPdaEvents = new List<Tuple<int, TAtmOrder>>();
NeedPdaEvents.Add(Tuple.Create(0, item));
NeedPdaEvents.Add(Tuple.Create(0, item));
var eventordids = NeedPdaEvents.Select(a => a.Item2.ID).ToList();
foreach (var dicobj in NeedPdaEvents)
{
var atmOrder = dicobj.Item2;
}