Vb.net 如何将重复列表转换为具有计数的列表？

我有一份（交易）清单：

如何将其转换为（交易缩短的）列表：

优雅地

使用LINQ和：

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由于我的类型和状态是object，我不得不稍微改变一下这个解决方案，主要是：

groupt By Key=String.Format（“{0}{1}”、t.type.Id.ToString（）、t.statut.Id.ToString（））改为Group

和

With{.type=Group.First（）.type.Id、.statut=Group.First.statut.Id、.quantite=Group.Count（）

Type | State  
----------------
boat | buy
boat | buy
boat | sell
car  | sell
car  | sell
car  | sell
plane| buy

Type | State | Quantity  
-----------------------
boat | buy   | 2
boat | sell  | 1
car  | sell  | 3
plane| buy|  | 1

Dim transactionGroups =
        From t In transactions
        Group t By Key = New With {
            .Type = t.Type,
            .State = t.State
        } Into Group
        Select New With {
            .Type = Key.Type,
            .State = Key.State,
            .Quantity = Group.Count()
        }

For Each tGroup In transactionGroups
    Dim type = tGroup.Type
    Dim state = tGroup.State
    Dim quantity = tGroup.Quantity  
Next