在linq中使用left join时，同时count，应该怎么做？谢谢。

from q in OneSet
join x in OneSet
on q.id equals x.ParentID into temp
from qx in temp.DefaultIfEmpty()
{
    //Count = ...
}

现在要查出x的Count的值，怎么做啊？谢谢。
[解决办法]
from q in OneSet
join x in OneSet
on q.id equals x.ParentID into temp
from qx in temp.DefaultIfEmpty()
select new
{
Count = qx==null?0:temp.Count()
}

[解决办法]
var q =
from a in OneSet
join b in TwoSet on a.ID equals b.ParentID
group a by new {AID=a.ID, AParentID=a.ParentID, AName=a.Name,AFlagStatus=a.flagStatus} into g
select new {g.Key, BCount=g.Count()};
foreach (var item in q)
{
//A记录信息：
item.Key.AID
item.Key.AParentID
item.Key.AName
item.Key.AFlagStatus
//对应B记录的数量：
item.BCount
}
[解决办法]

var query=from q in OneSet
join x in TwoSet
on q.id equals x.ParentID 
group q by new {AID=q.ID, AParentID=q.ParentID, AName=q.Name,AFlagStatus=q.flagStatus} into temp
select new 
{
  Key=temp.key,
  Count=temp.Count()
}