//解決iOS11躯畴，僅實(shí)現(xiàn)heightForHeaderInSection呻纹，沒有實(shí)現(xiàn)viewForHeaderInSection方法時(shí),section間距大的問題
[UITableView appearance].estimatedRowHeight = 0;
[UITableView appearance].estimatedSectionHeaderHeight = 0;
[UITableView appearance].estimatedSectionFooterHeight = 0;
//iOS11 解決SafeArea的問題括勺，同時(shí)能解決pop時(shí)上級(jí)頁面scrollView抖動(dòng)的問題
if (@available(iOS 11, *)) {
[UIScrollView appearance].contentInsetAdjustmentBehavior = UIScrollViewContentInsetAdjustmentNever;
}
