将列表（列表（类））转换为列表（类）

Question

我有一个类，它存储在字典内的列表中，如下所示：-

Public Class MyClass
    Public something As Integer
    Public something_else As Double
End Class

Dim my_dictionary As Dictionary (Of Integer, List (Of MyClass))

然后我需要提取其中一些列表并将它们转换为单个列表。我可以像这样提取必要的列表：-

Dim list_of_lists As List (Of List (Of MyClass)) =
    From dict_item As KeyValuePair (Of Integer, List (Of MyClass) In my_dictionary
        Where dict_item.Key < some_value
        Select dict_item.Value).ToList

但无法将这些转换为

Dim list_of_items As List (Of MyClass) = ...er...

我已经使用SelectMany 查看了here 和here 的问题，但我无法使用SelectMany 进行编译，而且C# 的用法（和解释）有点简洁。

使用

(From one_list In list_of_lists
    Select one_list.FindAll(Function(x) True)).ToList

只是创建另一个列表列表。

有人知道怎么做吗？

Answer 1

Dim list_of_items As List (Of MyClass) = list_of_lists.SelectMany(Function(list) list).ToList()

在查询语法中：

Dim items = From list In list_of_lists
            From item In list
            Select item
Dim list_of_items As List (Of MyClass) = items.ToList()