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尝试做一些我确定应该很简单的事情，但在 linq 和 VB 中挣扎。我有以下内容，我正在按属性对集合进行分组，然后想要访问我的组的属性。我遇到的问题是匿名打字。由于选项严格，我必须给出一个明确的类型，但我无法确定该类型应该是什么。以下内容无法编译，因为 t.HeadAccountKey 不是值（因为 t 具有对象类型）。所以要么我需要做一些转换，要么我的 linq 选择器是错误的，

public class TempObject
    public HeadKey as string
    Public SubKey as string
    Public SomeValue as decimal
end class

public class GroupTest
public sub RunTest
    dim collection new List(of TempObject) = GetTestCollection()

    Dim groupedValues As IEnumerable = From n In collection _
        Group By key = n.HeadKey Into Group Select HeadKeyValue = key, SubValues = Group

    for each t as object in groupedValues
    debug.print(t.HeadKeyValue)
        next

End sub

private function GetTestCollection() as List(of TempObject)
    dim result as new list(of tempobject)
    Dim x As New tempObject
    x.HeadAccountNumber = "A"
        x.SubAccountNumber = "B"
        x.Value = 500
        result.Add(x)
        x = New tempObject
        x.HeadAccountNumber = "A"
        x.SubAccountNumber = "C"
        x.Value = 600
        result.Add(x)
        x = New tempObject
        x.HeadAccountNumber = "B"
        x.SubAccountNumber = "D"
        x.Value = 100
    result.add(x)
    return result
end function
End class
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1 回答 1

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您不需要指定类型，至少使用Option Infer on（推荐，不要与 混淆Option Strict）。

所以以下工作：

Dim collection = GetTestCollection()
Dim groupedValues = From n In collection
    Group n By n.HeadKey Into Group

For Each t In groupedValues
    Dim hk = t.HeadKey
    Dim group = t.Group
Next
于 2012-04-24T11:56:31.307 回答