title: Update the UITextView content dynamically in a specific range
body: <p>I need to update the words dynamically in UiTextView content while TTS is playing without refresh the page. </p>
  
  <p>Problem: While tts playing for the each word delegate<code>(willSpeakRangeOfSpeechString:(NSRange)characterRange utterance:(AVSpeechUtterance *)utterance)</code> is calling. 
  so at that time i am updating the text color using <code>NSMutableAttributedString</code>.</p>
  
  <p>In this process the content in the textview is unstable because for each word page is refreshing.</p>
  
  <p>so i need to update the text in textview without refreshing the page.</p>
  
  <p>I wrote the code like this.</p>
  
  <blockquote>
    <p>NSMutableAttributedString *attrStr = [[NSMutableAttributedString
    alloc] initWithString:_theContent ]; </p>
    
    <p>[attrStr addAttribute:NSFontAttributeName value:[UIFont
    systemFontOfSize:self.fontSize] range:[self wholeArticleRange]];</p>
    
    <p>[attrStr addAttribute:NSForegroundColorAttributeName value:[UIColor
    redColor] range:theRange];</p>
    
    <p>textview.attributedText = attrStr;</p>
  </blockquote>
  
  <p>--In android we used <strong>spannable class</strong> to do this way. Is there any class in IOS like this?</p>
  
  <p>Kindly give us solution ASAP</p>
  
  <p>Thanks in advance. </p>