Audio file not played on the call but on local system - Skype for Business (C#)

Question

I have found some code HERE and modified the same to call a phone number using skype, play an audio file and then disconnect. However, there are two issues in this code.

1. Audio file which is being played can be heard on the local system but NOT in the phone call (the person receiving the call is not able to hear the audio played).

2. The call is not getting disconnected after audio file finishes playing.

   using Microsoft.Lync.Model;
   using Microsoft.Lync.Model.Conversation;
   using Microsoft.Lync.Model.Conversation.AudioVideo;
   using Microsoft.Lync.Model.Device;
   using Microsoft.Lync.Model.Extensibility;
   using System;
   using System.Collections.Generic;
   using System.Threading;
   using System.Windows.Forms;
   
   namespace LyncTest
   {
   public partial class frmCaller : Form
   {
       public frmCaller()
       {
           InitializeComponent();
       }
   
   private void btnCall_Click(object sender, EventArgs e)
   {
       //if this client is in UISuppressionMode...
       if (client.InSuppressedMode && client.State == ClientState.Uninitialized)
       {
           //...need to initialize it
           try
           {
               client.BeginInitialize(this.ClientInitialized, null);
           }
           catch (LyncClientException lyncClientException)
           {
               Console.WriteLine(lyncClientException);
           }
           catch (SystemException systemException)
           {
               if (LyncModelExceptionHelper.IsLyncException(systemException))
               {
                   // Log the exception thrown by the Lync Model API.
                   Console.WriteLine("Error: " + systemException);
               }
               else
               {
                   // Rethrow the SystemException which did not come from the Lync Model API.
                   throw;
               }
           }
       }
       else //not in UI Suppression, so the client was already initialized
       {
           //sign-in or contact selection
           SignInToLync();
       }
       SendLyncCall("+6512345678", "Hello, I am calling regarding a pending change request");
   }
   
   LyncClient client = LyncClient.GetClient();
   private void SignInToLync()
   {
       try
       {
           client.BeginSignIn("[email protected]", "[email protected]", "Pass@word99", HandleEndSignIn, null);
       }
       catch (LyncClientException lyncClientException)
       {
           Console.WriteLine(lyncClientException);
       }
       catch (SystemException systemException)
       {
           if (LyncModelExceptionHelper.IsLyncException(systemException))
           {
               // Log the exception thrown by the Lync Model API.
               Console.WriteLine("Error: " + systemException); 
           }
           else
           {
               // Rethrow the SystemException which did not come from the Lync Model API.
               throw;
           }
       }
   }
   
   Automation _automation = LyncClient.GetAutomation();
   ConversationWindow globalConv = null;
   public void SendLyncCall(string numberToCall, string textToSpeech)
   {
       var targetContactUris = new List<string> { numberToCall }; //"tel:+4900000000" 
   
       _automation.BeginStartConversation(AutomationModalities.Audio, targetContactUris, null, StartConversationCallback, null);
   
       while (this.globalConv == null)
       {
           Thread.Sleep(1);
       }
       if (globalConv != null)
       {
           //client.DeviceManager.EndPlayAudioFile(
           //  client.DeviceManager.BeginPlayAudioFile(@"C:\Temp\voice.wav", AudioPlayBackModes.AlertAndCommunication, false, AudioPlayed, null)
           //  );
       }
   }
   
   private void StartConversationCallback(IAsyncResult asyncop)
   {
       // this is called once the dialing completes..
       if (asyncop.IsCompleted == true)
       {
           ConversationWindow newConversationWindow = _automation.EndStartConversation(asyncop);
           globalConv = newConversationWindow;
           AVModality avModality = newConversationWindow.Conversation.Modalities[ModalityTypes.AudioVideo] as AVModality;
           avModality.ModalityStateChanged += ConversationModalityStateChangedCallback;
       }
   }
   
   /// <summary>
   /// Called when the client in done initializing.
   /// </summary>
   /// <param name="result"></param>
   private void ClientInitialized(IAsyncResult result)
   {
       //registers for conversation related events
       //these events will occur when new conversations are created (incoming/outgoing) and removed
       //client.ConversationManager.ConversationAdded += ConversationManager_ConversationAdded;
       //client.ConversationManager.ConversationRemoved += ConversationManager_ConversationRemoved;
   }
   
   private void ConversationModalityStateChangedCallback(object sender, ModalityStateChangedEventArgs e)
   {
       AVModality avModality = sender as AVModality;
       if (avModality != null)
       {
           switch (e.NewState)
           {
               case ModalityState.Disconnected:
                   avModality.ModalityStateChanged -= ConversationModalityStateChangedCallback;
                   break;
   
               case ModalityState.Connected:
                   avModality.ModalityStateChanged -= ConversationModalityStateChangedCallback;
                   //foreach (char c in "SOS")
                   //{
                   //    avModality.AudioChannel.BeginSendDtmf(c.ToString(), null, null);
                   //    System.Threading.Thread.Sleep(500);
                   //}
                   client.DeviceManager.EndPlayAudioFile(client.DeviceManager.BeginPlayAudioFile(@"C:\Temp\voice.wav",
                       AudioPlayBackModes.Communication, false, AudioPlayed, null));
                   break;
               case ModalityState.Invalid:
                   break;
               case ModalityState.Notified:
                   break;
           }
       }
   }
   
   private void AudioPlayed(IAsyncResult audioPlayed)
   {
       if(audioPlayed.IsCompleted == true)
       {
           client.ConversationManager.Conversations[0].End();
       }
   }
   private void HandleEndSignIn(IAsyncResult ar)
   {
       try
       {
           client.EndSignIn(ar);
       }
       catch (Exception e)
       {
           Console.Out.WriteLine(e);
       }
   }
   
   private void frmCaller_FormClosing(object sender, FormClosingEventArgs e)
   {
       GC.Collect();
   }
   }
   }
   

Any help would be appreciated. Thank you.

Answer 1

It was confirmed by Microsoft that this is not possible using client side code. I need to use UCMA and develop a server side solution for the same.