去掉顶部35pt的间距
设置tableHeaderView
tableView.tableHeaderView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, kScreenWidth, CGFLOAT_MIN)];
去掉底部20pt的间距
UIView *footerView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, self.view.bounds.size.width, CGFLOAT_MIN)];
tableView.tableFooterView = footerView;
