-(void)clickedButton:(id)selector {
 
    // delete as appropriate
 
   [self.navigationController pushViewController:viewController animated:YES];
   // or
 
    [self.view addSubview:theView];
 
   // or
 
   [self presentModalViewController:viewController animated:YES];
 
}这段代码执行后就跳出来了?这种功能怎么实现?