Manipulate and Dedupe Array of data for display into DataGrid

I have an array of data brought into my VB .Net program that follows the following format.

Order No.|Description|Colour|Size|Total Qty.|Order Date|Expected D.D.
2273448|NOK OPAQUE KNEE HIGH |BLACK |X |001 |02/12/2013 |05/12/2013
2231428|UX XR WARM HOLD UPS |NAVY |ONE SIZE |001 |02/12/2013 |05/12/2013
2231428|NHS SOFTHOLD HOLD-UP |BLACK |X |001 |02/12/2013 |05/12/2013
2265640|KX XR WARM TIGHTS |BLACK |XXL |001 |02/12/2013 |05/12/2013
2273448|NOK OPAQUE KNEE HIGH |BLACK |X |001 |02/12/2013 |05/12/2013
2231428|NHS SOFTHOLD HOLD-UP |BLACK |X |001 |02/12/2013 |05/12/2013
2231428|NHS SOFTHOLD HOLD-UP |NATURAL |X |001 |02/12/2013 |05/12/2013
2267461|WF-01 FLIP FLOP |BLACK |13 |001 |02/12/2013 |05/12/2013
2231428|NHS SOFTHOLD HOLD-UP |NATURAL |X |001 |02/12/2013 |05/12/2013
2273007|CR COTTON-RICH SOCK |BLACK |4-7 |001 |02/12/2013 |06/12/2013
2273127|TH THERMAL SOCK |MOSS |6-11 |001 |02/12/2013 |06/12/2013

This is a pre-formatted piped text file that I have no control over.

I am trying to bring this data into a VB DataGrid, but before I do, I want to de-dupe the values, whilst counting them, so I can display only pertinent data, without duplicate rows, so that the program user can then select the rows and work on all the associated rows (i.e. reducing the potential for human error.

The expected output to the DataGrid, based on the above, would be something like...

Order No | Lines on Order | Order Date | Expected Date
2273448  |2               |02/12/2013  |05/12/2013
2231428  |5               |02/12/2013  |05/12/2013
2265640  |1               |02/12/2013  |05/12/2013
2267461  |1               |02/12/2013  |05/12/2013
2273007  |1               |02/12/2013  |06/12/2013
2273127  |1               |02/12/2013  |06/12/2013

Here is the portion of the form code that is opening the file and retrieving the data...

Dim JDW_Row As String
Dim JDW_RowValues() As String

' Process JDW Order File into DataGrid

        Dim JDW_Reader As IO.StreamReader = New IO.StreamReader(File.OpenRead(FullPath), System.Text.Encoding.Default)

        ' Skip Header
        JDW_Reader.ReadLine()

        ' Start reading file contents
        Do Until JDW_Reader.EndOfStream

            ' read a record and split into fields

            JDW_Row = JDW_Reader.ReadLine()
            JDW_RowValues = Split(JDW_Row, "|")

        Loop

I get that for each member of JDW_RowValues, I need to ask 'have I seen you before' by writing it to an array and incrementing an associated counter or array value if its encountered again but I'm not sure of the code in VB .NET.

Can anyone suggest the best method?

Solution

 Class OrderItem
    Public Property OrderNo As String  ' ???
    Public Property Quantity As Integer 
    Public Property OrderDate As DateTime
    Public Property ExpectedDate As DateTime

    Sub New(newOrderNo)
       OrderNo = newOrderNo
    End Sub
 End Class

 Friend colOrderItems as New Dictionary(Of String, OrderItem)

 ' ... pseudo for adding in the loop

 Dim item as OrderItem

 Do Until JDW_Reader.EndOfStream
     If colOrderItems.ContainsKey(newOrderIDRead) Then
         ' increment quatity
         colOrderItems(newOrderIDRead).Quantity += newQuanReadValue

     Else
        ' add a new one
        item = New OrderItem(newOrderIDRead)
        item.Quantity = newQuanReadValue
         ...
         colOrderItems.Add(newOrderIDRead, item)
     End If
 Loop

The dictionary helps weed out duplicates because only one key of that value (OrderID) is allowed, and it is easy to find existing ones. A List(of OrderItem) would also work, but it does not inherently keep out dupes (which also partly depends on the definition of a dupe).