//解决iOS11关于隐藏导航栏后带有scrollView界面出现，下移问题
    if (@available(iOS 11.0, *)) {
        self.tableView.contentInsetAdjustmentBehavior = UIScrollViewContentInsetAdjustmentNever;
    } else {
        self.automaticallyAdjustsScrollViewInsets =NO;
    }