Linq ForEach with AddRange and Contains And Select

Question

我有一个foreach循环，我试图变成一个linq查询

List<CustomType> typeList=new List<CustomType>();
List<int> ListID=new List<int>();

foreach (Info info in SubDetails)
{
    if (typeList.Contains(info.TypeID))
    {
        ListID.Add(info.OrderID);
    }
}

现在我想把它变成一个linq循环

 SubDetails.ForEach(u => List.AddRange(
                    typeList.Contains(ID or something)
                    .Select(u.OrderID)));

但这显然不起作用，请引导我走向正确的方向

Answer 1

试试这个：

var ListID = SubDetails
                .Where(info => typeList.Any(type => type == info.TypeID)
                .Select(info => info.OrderID);

Answer 2

您可以将ListID填充为

SubDetails.Where(t => typeList.Exists(lst => lst.XXX == t.TypeID)).Select(id => id.OrderID)

Answer 3

试试这个。

var ListID = typelist.Join(SubDetails,tl=>tl,sd=>sd.TypeID,(tl,sd)=>sd.OrderID).ToArray();