VB.NET and LINQ query on a dictionary

Question

I need a simple LINQ query on VB.NET on the dictionary below, but I'm really new to the subject so I need your help.

    Protected Sub Page_Load(sender As Object, e As System.EventArgs) Handles Me.Load
        Dim appEnums As New Dictionary(Of Integer, String)

        appEnums.Add(1, "www.eva.com")
        appEnums.Add(2, "www.eva2.com")
        appEnums.Add(4, "www.evanetwork.com")
        appEnums.Add(5, "www.eva3.com")
        appEnums.Add(6, "www.eva4.com")
        appEnums.Add(7, "www.eva5.com")
        appEnums.Add(8, "www.eva6.com")
        appEnums.Add(9, "www.eva1.com")
        appEnums.Add(10, "www.eva7.com")

        Dim startSite As Integer = 1
        Dim mainSite As Integer = 4
        Dim returnSite As Integer = 5
    End Sub

What I need here is to retrieve a SINGLE website (dictionary value of string type) or NOTHING (if the query cannot find an affordable result) given those rules:

• The dictionary key (integer) must be greater than startSite and not equal to mainSite or returnSite (both must be exluded from the result)

Any hint?

EDIT: thanks for the replies so far! I'm not sure they would work btw have to test them, at a first glance there is something odd.

I found a solution myself and it works perfectly (can't believe it) but I think there should be a more "elegant" way to it (in vb.net always). waiting for suggestions :)

        Dim resultSite As String

        Try
            resultSite = appEnums.Where(Function(x) x.Key > startSite _
            AndAlso x.Key <> mainSite AndAlso x.Key <> returnSite) _
            .OrderBy(Function(x) x.Key).Select(Function(x) x.Value).First()
        Catch
            resultSite = Nothing
        End Try

Solution

Here is a slightly more refined LINQ statement.

Dim resultSite As String =
    appEnums.OrderBy(Function(kvp) kvp.Key)
        .SkipWhile(Function(kvp) kvp.Key <= startSite)
        .Where(Function(kvp) kvp.Key <> mainSite AndAlso kvp.Key <> returnSite)
        .Select(Function(kvp) kvp.Value).FirstOrDefault()

It differs from your solution in two places:

• It uses OrderBy first, so that it can use SkipWhile
• It uses FirstOrDefault so that it avoids the ugly try/catch block.

Comments

[dlras2]

I wouldn't use Skip, since it requires that the dictionary be in strictly ascending order.

[Admin]

yep. And i need just one yes and also need to return nothing if I'm on the last key already (startSite).

[Admin]

I found a solution myself and it works perfectly (can't believe it) but I think there should be a more "elegant" way to it (in vb.net always). waiting for suggestions :) I cannot post here for other 7 hours since I have low rep.. add in the main topic right now!