TextFragment.TextOffset Property

Definition

Namespace:

System.Speech.Synthesis.TtsEngine

Assembly:

System.Speech.dll

Package:

System.Speech v9.0.0-rc.2.24473.5

Gets or sets the starting location of the text in the fragment.

public:
 property int TextOffset { int get(); void set(int value); };

public int TextOffset { get; set; }

member this.TextOffset : int with get, set

Public Property TextOffset As Integer

Property Value

Int32

An int is returned or can be used to set the start location, in character, of the part of text string associated with this fragment to be spoken.

Examples

The example below is part of a custom speech synthesis implementation inheriting from TtsEngineSsml, and using the use of TextFragment, SpeechEventInfo, FragmentState, and TtsEventId.

The implementation of Speak

1. Receives an array of TextFragment instances and creates a new array of TextFragment instances to be passed to the Speak method on an underlying synthesis engine.

   Particular care is used to respect the TextOffset, TextLength on the original TextFragment when creating the TextToSpeak on the new TextFragment instances.

2. If the TtsEngineAction enumeration value by found from the Action property on the FragmentState returned by the State property of each TextFragment instance is Speak, the implementation

   • Translates Americanism to Britishisms in the text to be spoken.

   • If the EventInterest property on the ITtsEngineSite interfaces provided to the implementation support the WordBoundary event type, a SpeechEventInfo instance is used to create an event to drive a synthesizer progress meter is created.

3. A speech rendering engine is then called with the modified TextFragment array.

private const int WordBoundaryFlag = 1 << (int)TtsEventId.WordBoundary;  
private readonly char[] spaces = new char[] { ' ', '\t', '\r', '\n' };  
internal struct UsVsUk  
{  
  internal string UK;  
  internal string US;  
}  

override public void Speak (TextFragment [] frags, IntPtr wfx, ITtsEngineSite site)  
{  
  TextFragment [] newFrags=new TextFragment[frags.Length];  

  for (int i=0;i<frags.Length;i++){  
    newFrags[i].State=frags[i].State;  
    //truncate  
    newFrags[i].TextToSpeak = frags[i].TextToSpeak.Substring(frags[i].TextOffset,  
                               frags[i].TextLength);  
    newFrags[i].TextLength = newFrags[i].TextToSpeak.Length;  
    newFrags[i].TextOffset = 0;  
    if (newFrags[i].State.Action == TtsEngineAction.Speak) {  
      //Us to UK conversion  
      foreach (UsVsUk term in TransList) {  
      newFrags[i].TextToSpeak.Replace(term.US, term.UK);  
      }  
      //Generate progress meter events if supported  
      if ((site.EventInterest & WordBoundaryFlag) != 0) {  
      string[] subs = newFrags[i].TextToSpeak.Split(spaces);  

      foreach (string s in subs) {  
        int offset = newFrags[i].TextOffset;  
        SpeechEventInfo spEvent = new SpeechEventInfo((Int16)TtsEventId.WordBoundary,   
                (Int16)EventParameterType.Undefined,   
                 s.Length, new IntPtr(offset));  
        offset += s.Length;  
        if (s.Trim().Length > 0) {  
          SpeechEventInfo[] events = new SpeechEventInfo[1];  
          events[0] = spEvent;  
          site.AddEvents(events, 1);  
        }  
      }  
      }  
    }  
  }  

  _baseSynthesize.Speak(newFrags, wfx, site);  

}  

Remarks

The default value of this property is 0.