在一个label改变text的字体及颜色

 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:30.0] range:NSMakeRange(0, 5)];

[str addAttribute:NSFontAttributeName value:[UIFont fontWithName:@"HelveticaNeue-Bold" size:30.0] range:NSMakeRange(6, 12)];

[str addAttribute:NSFontAttributeName value:[UIFont fontWithName:@"Courier-BoldOblique" size:30.0] range:NSMakeRange(19, 6)];

label.attributedText = str;