The default Item property throws an exception if the requested key is not in the list
Imports System Imports System.Collections.Generic Public Class Example Public Shared Sub Main() Dim openWith As New SortedList(Of String, String) openWith.Add("A", "a") openWith.Add("B", "b") openWith.Add("C", "c") openWith.Add("D", "d") Try Console.WriteLine("For key = ""tif"", value = {0}.", _ openWith("tif")) Catch Console.WriteLine("Key = ""tif"" is not found.") End Try End Sub End Class