C# と VB.NET の質問掲示板

■No75130 (むしかえし さん) に返信

サンプル：

Public Class Class1
    Public ID As String
    Public Col1 As String
    Public Col2 As String
    Public Data2 As Class2

    Public Sub New(ID As String, Col1 As String, Col2 As String)
        Me.ID = ID
        Me.Col1 = Col1
        Me.Col2 = Col2
    End Sub

End Class

Public Class Class2
    Public ID As String
    Public Col4 As String
    Public Col5 As String
    Public Col6 As String


    Public Sub New(ID As String, Col4 As String, Col5 As String, COl6 As String)
        Me.ID = ID
        Me.Col4 = Col4
        Me.Col5 = Col5
        Me.Col6 = Col6
    End Sub

End Class



        Dim list1 As New List(Of Class1)
        Dim list2 As New List(Of Class2)

        list1.Add(New Class1("A101", "5101", "1125"))
        list1.Add(New Class1("A102", "1201", "2325"))
        list1.Add(New Class1("A103", "3301", "5225"))

        list2.Add(New Class2("A103", "XS335", "DS6521", "4"))
        list2.Add(New Class2("A105", "XS565", "DS1475", "5"))
        list2.Add(New Class2("A101", "XS256", "DS6625", "1"))

        For Each itm2 In list2
            Dim cpitm2 = itm2
            Dim itm1 = list1.Find(Function(it1) it1.ID = cpitm2.ID)
            If itm1 Is Nothing Then
                itm1 = New Class1(itm2.ID, "", "")
                list1.Add(itm1)
            End If
            itm1.Data2 = itm2
        Next

■No75159 (むしかえし さん) に返信

結果の確認なら
        For Each itm1 In list1
            Console.Write("{0}, {1}, {2}", itm1.ID, itm1.Col1, itm1.Col2)
            If itm1.Data2 IsNot Nothing Then
                Console.Write(", {0}, {1}, {2}", itm1.Data2.Col4, itm1.Data2.Col5, itm1.Data2.Col6)
            End If
            Console.WriteLine()
        Next


のようにすれば確認出来ます。

あくまで実装例ですのでそのまま使うのはやりたいことに適合するか分かりません。
構造が理解出来ないようなら使用しない方がよいでしょう。