方法一:

CGRect frame=CGRectMake(0, 0, 0,CGFLOAT_MIN);
self.tableView.tableHeaderView=[[UIView alloc]initWithFrame:frame];

方法二:

CGRect frame=CGRectMake(0, 0, 0,0.0001);
self.tableView.tableHeaderView=[[UIView alloc]initWithFrame:frame];