ChangeList里面会有重复的数据，这时可以这样去掉重复的item

// Remove duplicated info
var dup = ChangeList.Where(item => item.Stream.id == item.NewId).ToList();
dup.ForEach(item =>ChangeList.Remove(item));

删除掉符合某种条件的

var selected = list.Where(item => item.Used == true).ToList();
selected.ForEach(item => list.Remove(item));