ios uiscrollview uitableview 适配 ios11

if(@available(iOS11.0, *)) {

_bgScrollView.contentInsetAdjustmentBehavior=UIScrollViewContentInsetAdjustmentNever;

_bgScrollView.contentInsetAdjustmentBehavior=UIScrollViewContentInsetAdjustmentNever;

}

if(IS_IOS_11) {

_tbView.estimatedRowHeight=0;

_tbView.estimatedSectionHeaderHeight=0;

_tbView.estimatedSectionFooterHeight=0;

}