uiscrollview 取消顶部默认间距

  UIScrollView* scollView = [UIScrollView new];

    scollView.contentInset = UIEdgeInsetsZero;

    if (@available(iOS 11.0, *)) {

        scollView.contentInsetAdjustmentBehavior = UIScrollViewContentInsetAdjustmentNever;

       

    } else {

        // Fallback on earlier versions

    }

    if (@available(iOS 13.0, *)) {

            scollView.automaticallyAdjustsScrollIndicatorInsets = YES;

       } else {

           // Fallback on earlier versions

       }

    self.automaticallyAdjustsScrollViewInsets = NO;