VB.Net LINQ的数据表已存在

Question

我想使用Linq而非以下功能：

Friend Function IsCollectionInTable2(ByVal apps As DataTable, ByVal collectionId As String) As Boolean 
    For Each row As DataRow In apps.Rows 
     If row("CollectionId").ToString = collectionId Then Return True 
    Next 
    Return False 
End Function 

我能做的最好的是下面：

Friend Function IsCollectionInTable(ByVal apps As DataTable, ByVal collectionId As String) As Boolean 
    Return (From row In apps.AsEnumerable() 
      Where (row.Field(Of String)("CollectionId") = collectionId) 
      Select row.Field(Of String)("CollectionId")).Count > 0 
End Function 

我想用疑问，或对在上面的功能。性能可能是一个问题，

Answer 1

什么DataTable.Select Method (String)（对不起我的VB很差）

Dim expression As String 
    expression = string.Format("CollectionId = '{0}'", collectionId) 
    ' Use the Select method to find all rows matching the filter. 
    return apps.Select(expression).Count > 0 

Answer 2

我发现，似乎工作的解决方案：

Return (From row In apps.AsEnumerable() 
     Where row.Field(Of String)("CollectionId") = collectionId).Any() 

我希望这是一样快：

For Each row As DataRow In apps.Rows 
If row("CollectionId").ToString = collectionId Then Return True 
Next 
Return False