同一个lable前后显示不同的颜色和大小

NSMutableAttributedString *str = [[NSMutableAttributedString alloc] initWithString:@"Using NSAttributed String"];

    [str addAttribute:NSForegroundColorAttributeName value:[UIColor blueColor] range:NSMakeRange(0,5)];
    [str addAttribute:NSForegroundColorAttributeName value:[UIColor redColor] range:NSMakeRange(6,12)];
    [str addAttribute:NSForegroundColorAttributeName value:[UIColor greenColor] range:NSMakeRange(19,6)];
    [str addAttribute:NSFontAttributeName value:[UIFont fontWithName:@"Arial-BoldItalicMT" size:20.0] range:NSMakeRange(0,5)];
    [str addAttribute:NSFontAttributeName value:[UIFont fontWithName:@"HelveticaNeue-Bold" size:20.0] range:NSMakeRange(6,12)];
    [str addAttribute:NSFontAttributeName value:[UIFont fontWithName:@"Courier-BoldOblique" size:20.0] range:NSMakeRange(19,6)];
    _attrLable.attributedText = str;