TextView改变颜色

 if(sr!=null){
      String str=childlist.get(groupPosition).get(childPosition).getTitle();
      int indexOf = str.indexOf(sr);
      if(indexOf != -1){
       
       int end = indexOf+sr.length();
       SpannableStringBuilder builder = new SpannableStringBuilder(str );
       ForegroundColorSpan redSpan = new ForegroundColorSpan(Color.RED);
       builder.setSpan(redSpan, indexOf, end, Spannable.SPAN_EXCLUSIVE_INCLUSIVE); 
       itemtitle.setText(builder);
      }