UIAlertController 标题文字大小 颜色

NSString *title = [NSString stringWithFormat:@"\n恭喜您获得%d个红包\n", ];
    NSString *msg = @"\n把红包分享给微信好友，金额随机，可用于购买雪票和雪卡";
    UIAlertController * alert = [UIAlertController alertControllerWithTitle:title
                                                                    message:msg
                                                             preferredStyle:UIAlertControllerStyleActionSheet];
// titile字号处理
    NSMutableAttributedString *hogan = [[NSMutableAttributedString alloc] initWithString:title];
    [hogan addAttribute:NSFontAttributeName
                  value:[UIFont systemFontOfSize:20.0]
                  range:NSMakeRange(, title.length)];
    [alert setValue:hogan forKey:@"attributedTitle"];
//

    UIAlertAction *sureAction = [UIAlertAction actionWithTitle:@"给好友发红包" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
        [self shareAction];
    }];
    [alert addAction:sureAction];

    alert.view.tintColor = APP_MAIN_COLOR;
    UIAlertAction *cancelAction = [UIAlertAction actionWithTitle:@"取消"
                                                           style:UIAlertActionStyleCancel
                                                         handler:nil];
    [alert addAction:cancelAction];

    [self presentViewController:alert animated:YES completion:nil];