Script Task Error?

I have the following code inside a Script task:

Imports System

Imports System.Data

Imports System.Math

Imports Microsoft.SqlServer.Dts.Runtime

Imports System.Collections

Public Class ScriptMain

Public Sub Main()

Dim nm As String = "ship_metrics_rpt_*.csv"

Dim files As ObjectModel.ReadOnlyCollection(Of String) = My.Computer.FileSystem. _

GetFiles(CStr(Dts.Variables("MainPath").Value))

If files.Count > 0 Then

Dim dic As Generic.SortedDictionary(Of Date, String)

For a As Integer = 1 To files.Count

If files(a) Like nm Then

Dim nfo As System.IO.FileInfo = My.Computer.FileSystem.GetFileInfo(files(a))

dic.Add(nfo.CreationTime, files(a))

End If

Next

If dic.Count > 0 Then

Dim FinalFiles(dic.Count - 1) As String

Dim count As Integer

For Each kvp As Generic.KeyValuePair(Of Date, String) In dic

FinalFiles(count) = kvp.Value

Next

End If

End If

Dts.TaskResult = Dts.Results.Success

End Sub

The following exception gets thrown at "If files.Count > 0 Then"

"Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index"

Why?

Thanks for your help

Has MainPath been passed in as a variable? It is scoped properly?|||

Yes it's been passed. You can insert "msgbox files.count" before "if files.count > 0" and get a count just fine. I don't understand it.

|||There are a number of problems here (easily fixed though)

1 . Fence post condition. The ReadOnlyCollection index starts at 0, not 1.
Change

For a As Integer = 1 To files.Count

To

For a As Integer = 0 To files.Count -1

2. Unitialized Variable:

Change

Dim dic As Generic.SortedDictionary(Of Date, String)

To

Dim dic As Generic.SortedDictionary(Of Date, String) = New Generic.SortedDictionary(Of Date, String)

|||Ah - I didn't catch the uninitialized part - that should fix it - thanks.