How to enable EWS Tracing using Exchange Web Services (EWS) Managed API in VB.net?

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Debugging a Web service–based application can be difficult because part of the processing is performed on a computer to which you do not have access. Because you cannot step through the code on the server, it can be helpful to see the XML requests and responses that are exchanged between the client and the server to determine which part of the application is causing an error. When you are using the Microsoft Exchange Web Services (EWS) Managed API, you can use the tracing methods on the ExchangeService object to capture the XML request that is sent to Exchange Web Services and the response that the server returns to the application.

To enable tracing on the ExchangeService object:

 Dim _exchangeService As New ExchangeService

 Dim TC As New EWSTrace.TraceListener

 _exchangeService.TraceFlags = TraceFlags.All

 _exchangeService.TraceEnabled = True

 _exchangeService.TraceListener = TC

The following code example shows simple object that implements the ITraceListener interface and stores the traced requests and responses in XML or text files.

 'NOTE: Following programming examples is for illustration only, without warranty either expressed or implied,

 'including, but not limited to, the implied warranties of merchantability and/or fitness for a particular purpose. 
'This sample code assumes that you are familiar with the programming language being demonstrated and

 'the tools used to create and debug procedures. This sample code is provided for the purpose of illustration only and is not intended to be used in a production environment. 

 Imports System

 Imports System.Text

 Imports Microsoft.Exchange.WebServices.Data

  

 Namespace EWSTrace

  

     Class TraceListener

         Implements ITraceListener

  

         Public Sub Trace(ByVal traceType As String, ByVal traceMessage As String) Implements ITraceListener.Trace

             CreateXMLTextFile(traceType + " --- " + traceMessage.ToString())

         End Sub

  

         Private Sub CreateXMLTextFile(ByVal traceContent As String)

             'Get the path of the application to create log files at

             Dim strPath As String = System.AppDomain.CurrentDomain.BaseDirectory

             strPath = strPath + "\\EWSLog.txt"

             Dim FS As System.IO.FileStream

             If System.IO.File.Exists(strPath) = False Then

                 FS = System.IO.File.Create(strPath)

             Else

                 FS = System.IO.File.OpenWrite(strPath)

             End If

             FS.Close()

  

             ' Create an instance of StreamWriter to write text to a file.

             Dim sw As System.IO.StreamWriter = System.IO.File.AppendText(strPath)

             sw.WriteLine(System.DateTime.Now.ToString() + " : " + traceContent)

             sw.Close()

             FS = Nothing

             sw = Nothing

         End Sub

     End Class

 End Namespace

For reference and C# sample code snippet refer: