scrollView铺满全屏

在viewController中添加scrollView并铺满全屏，隐藏导航条，设置scrollView上下左右间距为0，此种情况上部会留出状态栏高度，iPhone X上下部会留出34，都无法铺满全屏
解决如下：

if (@available(iOS 11.0, *)) {
  self.scrollView.contentInsetAdjustmentBehavior = UIScrollViewContentInsetAdjustmentNever;
  }else{
  self.automaticallyAdjustsScrollViewInsets = NO;
 }