iOS11 tableView内容向下偏移20pt或向下偏移64pt的问题?

默认情况下self.extendedLayoutIncludesOpaqueBars = NO 扩展布局不包含导航栏，

默认情况下self.automaticallyAdjustsScrollViewInsets = YES 自动计算滚动视图的内容边距，会往下偏64pt

// OC
self.extendedLayoutIncludesOpaqueBars = YES;
if (@available(iOS 11.0, *)) {
        self.tableView.contentInsetAdjustmentBehavior = UIScrollViewContentInsetAdjustmentNever;
} else {
        self.automaticallyAdjustsScrollViewInsets = NO;
}

// Swift
        self.extendedLayoutIncludesOpaqueBars = true
        if #available(iOS 11.0, *) {
            self.meTable?.contentInsetAdjustmentBehavior = .never
        } else {
            self.automaticallyAdjustsScrollViewInsets = false
        }