Problem: Filtering similar items in a listbox

[r00tb0x]

I have a listbox already filled with links from a search engine. I am trying to filter out some of the links from the same domain:

Error
http://abc.net.au/news/stories/test/index.html
Test cricket - Wikipedia, the free encyclopedia <---- remove this link because same as first entry

I've tried many things with no success. Here is my existing code for FilterButton_Click:

    Private Sub FilterButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles FilterButton.Click

        'Search and remove same site links'

        Dim arrayclean As ArrayList = New ArrayList()
        Dim thing As String
        For i As Integer = ResultsBox.Items.Count - 1 To 0 Step -1
            Dim check As Match = System.Text.RegularExpressions.Regex.Match(ResultsBox.Items(i), "http://.*?/")
            If ResultsBox.Items(i).Contains(check.ToString) Then

            Else
                arrayclean.Add(ResultsBox.Items.Item(i))
            End If
        Next
        ResultsBox.Items.Clear()
        For Each thing In arrayclean
            ResultsBox.Items.Add(thing)
        Next
        ResultsCnt.Text = ResultsBox.Items.Count
    End Sub

It seems so simple in my head, it just isn't working for me.

 

[JohnH]

Dim hosts As New Dictionary(Of String, String)
For Each url As String In Me.ResultsBox.Items
    hosts(New Uri(url).Host) = url
Next
Me.ResultsBox.DataSource = New List(Of String)(hosts.Values)

 

[r00tb0x]

That worked beautifully. Thanks a million. I had never heard of the dictionary class or the uri.host property.

 

[MattP]

Another option would be to let LINQ enumerate your Items collection and select only the Host part of your Uri.

        Me.ResultsBox.DataSource = (From url In Me.ResultsBox.Items
                                  Select New Uri(url).Host).Distinct.ToList