修改Navigationcontroller的title字体大小

修改Navigationcontroller的title字体大小：

    NSString *title = @"标题";    CGSize titleSize = [title sizeWithAttributes:@{NSFontAttributeName:[UIFont systemFontOfSize:EQAdapter(15)]}];    UILabel *titleLabel = [[UILabel alloc] initWithFrame:CGRectMake((SCREEN_WIDTH - titleSize.width)/ 2, (SCREEN_HEIGHT - titleSize.height) / 2, titleSize.width, titleSize.height)];    titleLabel.text = title;    titleLabel.textColor = [UIColor whiteColor];    self.navigationItem.titleView = titleLabel;