SpeechUtitlity.cs

using System;
using System.Linq;
using System.Threading.Tasks;
using System.Windows;
using Windows.Foundation;
using Windows.Phone.Speech.Synthesis;

namespace Utilities
{
  public class SpeechUtility : IDisposable
  {
    protected SpeechSynthesizer synth;

    protected string text;

    protected string[] parts;

    protected int max;

    protected IAsyncAction speakTask;

    public int Count { get; set; }


    /// <summary>
    /// Initializes a new instance of the <see cref="SpeechUtility"/> class.
    /// </summary>
    /// <param name="text">The text.</param>
    public SpeechUtility(string text)
    {
      synth = new SpeechSynthesizer();
      this.text = text;
      parts = this.text.Split(' '); // create a bookmark after each word
      max = this.parts.Length;

      synth.BookmarkReached += BookmarkReached;
    }


    /// <summary>
    /// Speaks the text.
    /// </summary>
    /// <param name="start">The start count.</param>
    /// <returns></returns>
    public void Speak(int? start = null)
    {
      if (start.HasValue)
      {
        Count = start.Value;
      }

      speakTask = synth.SpeakSsmlAsync(CreateSSML());
    }


    /// <summary>
    /// Pauses the speak task.
    /// </summary>
    /// <returns></returns>
    public void Pause()
    {
      speakTask.Cancel();
    }


    /// <summary>
    /// Creates the SSML.
    /// </summary>
    /// <returns></returns>
    protected string CreateSSML()
    {
      // restart reading when the END was reached before
      if (Count == max)
      {
        Count = 0;
      }

      String ssmlText = "<speak version=\"1.0\" xmlns=\"http://www.w3.org/2001/10/synthesis\" xml:lang=\"en-US\">";
      ssmlText += "<![CDATA[";

      for (int i = Count; i < max; i++)
      {
        ssmlText += parts[i];
        ssmlText += "]]><mark name=\"PART" + i.ToString() + "\"/><![CDATA[";
      }
      ssmlText += "]]><mark name=\"END\"/>";
      ssmlText += "</speak>";

      return ssmlText;
    }


    /// <summary>
    /// Reached a new bookmark.
    /// </summary>
    /// <param name="sender">The sender.</param>
    /// <param name="e">The <see cref="SpeechBookmarkReachedEventArgs"/> instance containing the event data.</param>
    protected void BookmarkReached(object sender, SpeechBookmarkReachedEventArgs e)
    {
      Count++;

      if (e.Bookmark == "END")
      {
        Pause();
        Count = 0;
      }
    }



    /// <summary>
    /// Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
    /// </summary>
    public void Dispose()
    {
      synth.Dispose();
    }
  }
}