A collection of problems encountered during the development of iOS11

//Solve the problem of large section spacing when iOS11 only implements heightForHeaderInSection and does not implement the viewForHeaderInSection method
[UITableView appearance].estimatedRowHeight = 0;
[UITableView appearance].estimatedSectionHeaderHeight = 0;
[UITableView appearance].estimatedSectionFooterHeight = 0;

//Solve The problem of SafeArea can also solve the problem of scrollView jitter on the upper page when popping
if (@available(iOS 11, *)) {

[UIScrollView appearance].contentInsetAdjustmentBehavior = UIScrollViewContentInsetAdjustmentNever; 

//iOS11 solves the problem of SafeArea and can also solve the problem of scrollView jitter on the upper page when pop

}