hi all, i'm in troubled show lyrics .i use uitextview show lyrics code snips

    IBOutlet UILabel *lrcshow;
   IBOutlet UITextView *showlrc;

 self.lrcshow.text = [lrcDictss objectForKey:[NSString stringWithFormat:@"%d",(int)self.player.currentTime]];
 if (self.lrcshow.text!=nil) {

  NSRange selection = [self.showlrc.text rangeOfString:self.lrcshow.text]; 
  if( selection.location != NSNotFound )
  { 

   showlrc.selectedRange = selection; 



  }
 }

lyrics line by line scrolling show,the problem is now playing(selectedRange) lyric is not highlight, i want this line highlight how can i code ? any suggestion?or use calayer ?cgcontext quartz core instead it? how can i code ?

ps.use uitextview show is rigidly ,not smooth!

lr style show pic url this is my app style: http://www.flickr.com/photos/53054715@N05/5359722887/

this is good style: flickr.com/photos/53054715@N05/5360345226/