Question

当我在第三个视图中按下取消按钮时，我想直接回到第一个视图。我还想删除第二个视图。我怎么能这样做？

这是代码。

// this part is in the first view.
self.second = [SecondController alloc] init];
[self.view addSubview:second.view];

// this part is in the second view.
ThirdController *thirdController = [[ThirdController alloc] initWithStyle:UITableViewStyleGrouped];             
self.navigationController = [UINavigationController alloc] initWithRootViewController:thirdController];
[self.view addSubview:navigationController.view];

// this part is in the third view.
- (void)cancel {
    [self.view removeFromSuperview]; // this only goes to the second view.
}

编辑：我可以在被叫contoller中使用popToViewController吗？我的应用程序崩溃了。我认为popToViewController只能用于调用控制器。并且在推送时使用popToViewController。我确实添加了不推。

Answer 1

[self.navigationController popToViewController:[[self.navigationController viewControllers] objectAtIndex:0] animated:YES];

Answer 2

popToViewController:animated:是在导航控制器堆栈中弹出视图控制器时使用的UINavigationController方法。它不适合这种情况。

此用户正在添加子视图，而不是在导航控制器堆栈上推送它们。

作为一个注释，它似乎是设计问题应该使用导航控制器，第一个视图作为根控制器，然后第二个推入堆栈，第三个推进堆栈。那么你所要做的就是[self.navigationController popToRootViewControllerAnimated:YES]。

我认为如果您想保留当前的架构，这将有效：

// this part is in the third view.
- (void)cancel {
    // remove the second view (self.view.superview) from the first view
    [self.view.superview removeFromSuperView];
    // can't recall, possibly you still need to remove the third view, but i think removing the superview will do it.
    // [self.view removeFromSuperView];
}

如果您更喜欢尝试UINavigationController路线，那么最简单的方法是在Xcode中创建一个新项目，并选择基于导航的应用程序或主从应用程序的类型。这将在笔尖中创建UINavigationController并将其添加到窗口中。然后，您可以将Interface Builder中的根视图控制器设置为FirstViewController类。

如果您希望在代码中创建UINavigationController，那么这也是可能的。无论您是在IB中还是在代码中的nib中创建UINavigationController，我都会在下面显示您需要的其他代码。

我还建议您阅读View Controller Programming Guide for iOS。

在您的app代理或其他代码中：

-(void)application:(UIApplication*)application didFinishLaunchingWithOptions:(NSDictionary*)launchOptions [
    // I would recommend setting up the UINavigationController and FirstViewController as IBOutlets in your nib, but it can be done in code.
    FirstViewController* fvc = [[FirstViewController alloc] initWithNibName:@"FirstView" bundle:nil];
    UINavigationController* navController = [[UINavigationController alloc] initWithRootViewController:fvc];

    [window addSubView:navController.view];
    [window makeKeyAndVisible];

    [fvc release];
    [navController release];
}

在第一个视图控制器中：

SecondViewController* svc = [[SecondViewController alloc] initWithNibName:@"SecondView" bundle:nil];
[self.navigationController pushViewController:svc animated:YES];
[svc release];

在第二个视图控制器中：

ThirdViewController* tvc = [[ThirdViewController alloc] initWithNibName:@"ThirdView" bundle:nil];
[self.navigationController pushViewController:tvc animated:YES];
[tvc release];

在第三个视图控制器中：

-(void)cancel {
    // returns to the first view controller
    [self.navigationController popToRootViewControllerAnimated:YES];
}

Answer 3

使用

- (NSArray *)popToViewController:(UIViewController *)viewController animated:(BOOL)animated

返回特定的视图控制器。

Answer 4

试试这个：

[self.navigationController popToViewController:[self.navigationController.viewControllers objectAtIndex:1] animated:YES];

这将弹出到索引1处的视图。希望帮助！

Answer 5

// this part is in the third view.
- (void)cancel {
    self.first = [SecondController alloc] init];
    [self.view addSubview:second.view];
}

我认为，如果你不需要担心删除视图，以后会删除。

如何直接从第三个视图返回第一个视图？

5 个答案: