这段代码有什么问题？尝试将 navController 加载到模态视图控制器上

发布于 2024-11-27 11:09:38 字数 922 浏览 4 评论 0原文

我有一个 UIViewcontroller，我想将其推送到 UINavigationController 上，而 UINavigationController 又会使用 PresentModalViewController:animated 推送到模态视图上。

这是我的代码：

TargetViewController *targetViewController = [[[TargetViewController alloc] init] autorelease];
UINavigationController *targetNavController = [[[UINavigationController alloc] initWithRootViewController:targetViewController] autorelease];
[self presentModalViewController:targetNavController animated:YES];

当代码运行时，模态视图按预期加载，但是在调用dismissModalViewControllerAnimated:之后，模态视图向下滑动并且应用程序崩溃。

我在 gdb 中收到以下错误： -[CALayer保留]：发送到已释放实例的消息

问题的第一部分：上面的代码有什么本质上的错误吗？

第二部分：如果上面的代码没有问题，接下来我应该在哪里调试？

其他信息： 当我不释放或自动释放navController时，它工作正常。但是 Instruments 会显示废弃的内存，我只能假设 navController 没有被释放。控制器

也许是模态视图我知道崩溃与上述 ViewController、navController 和模态视图的内存管理有关，因为我的代码在弄乱此代码之前正在运行。

原文

I have a UIViewcontroller that I want to push onto a UINavigationController, which in turn would push onto a modal view using presentModalViewController:animated.

Here's my code:

TargetViewController *targetViewController = [[[TargetViewController alloc] init] autorelease];
UINavigationController *targetNavController = [[[UINavigationController alloc] initWithRootViewController:targetViewController] autorelease];
[self presentModalViewController:targetNavController animated:YES];

When code is run, the modal view loads as expected, but after dismissModalViewControllerAnimated: is called, the modal view slides down and the app crashes.

I get the following error in gdb:
-[CALayer retain]: message sent to deallocated instance

First part of question: is there anything inherently wrong with the above code?

Second part: if there is nothing wrong with above code, where should I look next to debug?

Additional info:
When I don't release or autorelease the navController, it works fine. But Instruments will show abandoned memory, which I can only assume is the navController not being released. Maybe the modal view controller

P.S. I know that the crash is related to the memory management of the above ViewController, navController and modal view, because my code was working prior to messing with this code.

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铁轨上的流浪者 2024-12-04 11:09:38

您通常不会将 navController 作为视图推送，因为导航控制器充当根控制器。视图是从 navController 推送的。一旦推送了一个视图，您就可以以模态方式呈现下一个视图。

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从来不烧饼 2024-12-04 11:09:38

如果不使用 autorelease 会发生什么？

IE：

TargetViewController *targetViewController = [[TargetViewController alloc] init];
UINavigationController *targetNavController = [[UINavigationController alloc] initWithRootViewController:targetViewController];
[targetViewController release];
[self presentModalViewController:targetNavController animated:YES];
[targetNavController release];

What happens if you don't use autorelease?

I.E.:

TargetViewController *targetViewController = [[TargetViewController alloc] init];
UINavigationController *targetNavController = [[UINavigationController alloc] initWithRootViewController:targetViewController];
[targetViewController release];
[self presentModalViewController:targetNavController animated:YES];
[targetNavController release];

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