modal方式跳转控制器

1给目标控制器添加关闭按钮

@implementation htmlViewController 
(void)viewDidLoad {
    [super viewDidLoad];
    self.navigationItem.leftBarButtonItem=[[UIBarButtonItem alloc]initWithTitle:@"关闭" style:UIBarButtonItemStyleDone target:self action:@selector(close)]; 
}


-(void)close{
    
    [self dismissViewControllerAnimated:YES completion:nil];//关闭正在显示的控制器
}

end

2把目标控制器包装在UINavigationController里，也就是设置成UINavigationController对象的根控制器

 htmlViewController *vc=[[htmlViewController alloc]init];

 UINavigationController *nav=[[UINavigationController alloc]initWithRootViewController:vc];    

[self presentViewController:nav animated:YES completion:nil];