[RESOLVED] Combine Three List(Of string) to listview LINQ

[kayleigh]

Hi so basically i have Three Lists that i wont to combine into One to add to a ListView.

So ListViewItem 0 Text would be the first lists index 0, the next lists index 0 would be it's sub item, and finally the third lists index 0 would be another sub item.

The next ListViewItem would be index 1 from the first lists. Just wondered if this is ok. It works.

        Dim one As New List(Of String)({"OneZero", "OneOne", "OneTwo"})
        Dim two As New List(Of String)({"TwoZero", "TwoOne", "TwoTwo"})
        Dim three As New List(Of String)({"ThreeZero", "ThreeOne", "ThreeTwo"})

        Dim query = (
        From item1
        In one
        From item2
        In two
        From item3
        In three
        Select New ListViewItem(New String() {item1, item2, item3})).ToArray

[kayleigh]

Just noticed this will duplicate each item more then once.

[dday9]

Don't know to much about LINQ myself, but this is how I'd do it:

        Dim one As New List(Of String)({"OneZero", "OneOne", "OneTwo"})
        Dim two As New List(Of String)({"TwoZero", "TwoOne", "TwoTwo"})
        Dim three As New List(Of String)({"ThreeZero", "ThreeOne", "ThreeTwo"})

        Dim col1, col2, col3 As New ColumnHeader
        ListView1.Columns.AddRange({col1, col2, col3})

        For i As Integer = 0 To one.Count - 1
            Dim new_item As New ListViewItem(one.Item(i))
            new_item.SubItems.AddRange({two.Item(i), three.Item(i)})
            ListView1.Items.Add(new_item)
        Next

[kayleigh]

Hi and thank you for the reply. I was using a for loop but trying to practice LINQ. I know LINQ is not always the answer but trying to learn more

[kayleigh]

Still struggling. I guess is that the only way by looping the first array by count?

[jmcilhinney]

Because you have the data in three different collections, you need to get an index from somewhere to get the three items to combine. You would normally do that using the loop counter in a For loop. You can use the Enumerable.Range method though, e.g.

ListView1.Items.AddRange(Enumerable.Range(0, list1.Count).
                                    Select(Function(i) New ListViewItem({list1(i), list2(i), list3(i)})).
                                    ToArray())

Obviously that assumes that the lists are all the same length, or at least that list1 is not longer than the other two.

[kayleigh]

Perfect as always