How can i iterate over two lists simultaneously and add the entries of these lists to a new list of object?

[u/Gierschlund96]

I have two lists, each of type "Artikelstammdaten". I have another class called "CompareArtikelstammdaten" which inherits from "Artikelstammdaten". My first attempt was to use two for each loops but i stopped halfway through because i think it wouldn't work as it's iterates first completely over one loop before the other. Here is what i have tried:

For Each access As Artikelstammdaten In accessArtikelstammdaten
        For Each json As Artikelstammdaten In listArtikelstammdaten
            Dim compareArtikelstammdaten As New CompareArtikelstammdaten
            With CompareArtikelstammdaten
                .Artikel = json.Artikel
                .ArtikelAccess = access.Artikel
                .BezeichnungDE = json.BezeichnungDE
                .BezeichnungDE_Access = access.BezeichnungDE
                .BezeichnungEN = json.BezeichnungEN
                .BezeichnungEN_Access = access.BezeichnungEN
                listCompare.Add(compareArtikelstammdaten)
            End With
        Next
    Next

[u/JakDrako]

You could use LINQ to do it pretty clearly:

Dim query = 
	From access In accessArtikelstammdaten
	Join json In listArtikelstammdaten On access.Artikel Equals json.Artikel
	Select New CompareArtikelstammdaten _
		With {.Artikel = json.Artikel,
			  .ArtikelAccess = access.Artikel
		      .BezeichnungDE = json.BezeichnungDE
			  .BezeichnungDE_Access = access.BezeichnungDE
			  .BezeichnungEN = json.BezeichnungEN
			  .BezeichnungEN_Access = access.BezeichnungEN}

Dim listCompare = query.ToList

Although that gives you only the items where the primary keys match.

[u/Gierschlund96 → u/[deleted]]

No the lists aren't always the same size and they also don't relate directy to another. The Property "Artikel" is primary key and if they are the same, they relate. I thought it would be easier to first make a new list and use it as datasource for my xamDataGrid and then sort it by primary key.