VB.NET: Cancel Delivery Of A Letter with CancelDelivery()


  1. Create a new Console Application project and add a web reference.
  2. Copy the entire code below, delete anything written in your application and paste the code there.
  3. Replace the values of the Const lines with your details:
    • Replace MyUsername and MyPassword with your PostalMethods user details.
    • Replace "ID" with the LetterID for which you would like to cancel.
  4. Start your application. If the response is -3000, you will see the status report. If the response is any other number, check the Web Service Status Codes section.
Imports System.IO
Module Module1
    Sub Main()
        Const MyUsername As String = "MyUsername"
        Const MyPassword As String = "MyPassword"
        Const ID As Integer = 0
        Dim objPM As New com.postalmethods.api.PostalWSSimple()
        Dim lngResult As Long
        ' Invoke the CancelDelivery method
        lngResult = objPM.CancelDelivery(MyUsername, MyPassword, ID)
        ' Check response status
        If lngResult = -3000 Then
            ' -3000 means the request was successfully marked for cancellation.
            Console.WriteLine("Request has been cancelled")
            ' A value less than -3000 means an error occurred.
            ' See the PostalMethods Status Codes: http://www.postalmethods.com/statuscodes.
            Console.WriteLine("Error is:" & lngResult)
        End If
        ' In debug mode, the following lines prevent your console application from closing automatically upon termination
        Console.WriteLine("Hit ENTER to terminate application")
    End Sub
End Module