我有一个视图,它使用 .sheet() 以模态方式呈现另一个 ChildView 我想在关闭此工作表时关闭 ParentView。所以就有了onDismiss回调。 然而当我添加
@Environment(\.presentationMode) var presentationMode
然后呈现表单,它会因此类错误而崩溃
libc++abi:以 NSException 类型的未捕获异常终止 *** 由于未捕获的异常“NSInvalidArgumentException”而终止应用程序,原因:“应用程序试图呈现 模态视图控制器 <TtGC7SwiftUI29PresentationHostingControllerVS_7AnyView: 0x7ffc07175c60> 已经由 <TtGC7SwiftUI19UIHostingControllerGVS_15ModifiedContentVS_7AnyViewVS_12RootModifier_: 0x7ffc04438c00>。'以未捕获的类型异常终止 NSException CoreSimulator 757.5 - 设备:iPhone 12 Pro (DEE900D2-F542-496C-9000-14498B9AA407) - 运行时:iOS 14.5 (18E182) - 设备类型:iPhone 12 Pro
不使用此环境属性一切正常。 似乎工作表尝试多次呈现自己,然后该属性可用。 但在其他屏幕(视图)上一切正常。
*** First throw call stack:
(
0 CoreFoundation 0x0000000113b4ffba __exceptionPreprocess + 242
1 libobjc.A.dylib 0x00000001136cdff5 objc_exception_throw + 48
2 UIKitCore 0x0000000121df4f32 -[UIViewController _presentViewController:withAnimationController:completion:] + 6016
3 UIKitCore 0x0000000121df593c __63-[UIViewController _presentViewController:animated:completion:]_block_invoke + 98
4 UIKitCore 0x0000000121e1049c -[_UIViewControllerTransitionCoordinator _applyBlocks:releaseBlocks:] + 294
5 UIKitCore 0x0000000121e0c70e -[_UIViewControllerTransitionContext _runAlongsideCompletions] + 126
6 UIKitCore 0x0000000121e0c482 -[_UIViewControllerTransitionContext completeTransition:] + 106
7 UIKitCore 0x0000000122a2f3cc -[UITransitionView notifyDidCompleteTransition:] + 247
8 UIKitCore 0x0000000122a2f069 -[UITransitionView _didCompleteTransition:] + 1422
9 UIKitCore 0x0000000122a68e7a -[UIViewAnimationBlockDelegate _didEndBlockAnimation:finished:context:] + 779
10 UIKitCore 0x0000000122a39831 -[UIViewAnimationState sendDelegateAnimationDidStop:finished:] + 231
11 UIKitCore 0x0000000122a39dd6 -[UIViewAnimationState animationDidStop:finished:] + 263
12 UIKitCore 0x0000000122a39f57 -[UIViewAnimationState animationDidStop:finished:] + 648
13 QuartzCore 0x00000001122a8dc0 _ZN2CA5Layer23run_animation_callbacksEPv + 308
14 libdispatch.dylib 0x000000011ab8b74e _dispatch_client_callout + 8
15 libdispatch.dylib 0x000000011ab99b3f _dispatch_main_queue_callback_4CF + 1152
16 CoreFoundation 0x0000000113abd8f8 __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 9
17 CoreFoundation 0x0000000113ab8169 __CFRunLoopRun + 2781
18 CoreFoundation 0x0000000113ab71a7 CFRunLoopRunSpecific + 567
19 GraphicsServices 0x0000000121151d85 GSEventRunModal + 139
20 UIKitCore 0x000000012251d4df -[UIApplication _run] + 912
21 UIKitCore 0x000000012252239c UIApplicationMain + 101
22 SwiftUI 0x0000000115b15c36 $s7SwiftUI17KitRendererCommon33_ACC2C5639A7D76F611E170E831FCA491LLys5NeverOyXlXpFAESpySpys4Int8VGSgGXEfU_ + 119
23 SwiftUI 0x0000000115b15bbd $s7SwiftUI6runAppys5NeverOxAA0D0RzlF + 143
24 SwiftUI 0x0000000115652384 $s7SwiftUI3AppPAAE4mainyyFZ + 61
25 Pro 0x0000000104d6bf40 $s3Pro0A3AppV5$mainyyFZ + 48
26 Pro 0x0000000104d6bfd4 main + 20
27 libdyld.dylib 0x000000011ac19bbd start + 1
示例代码如下所示
struct ParentView: View {
@Environment(\.presentationMode) var presentationMode
var body: some View {
mainButton
.sheet(
item: $viewModel.item,
onDismiss: {
},
content: { summary in
ChildView()
}
)
}
}
好吧,我找到了解决方案。导致问题的原因是,当存在 Environment(.presentationMode) 时,此视图上会进行一些刷新 .sheet(item:) 依赖于需要 id 的可识别类型。 它有这个 id,但如果它使用可选标识符,如
var id: String { myId ?? UUID().uuidString }
当没有这个 Environment 时,这个底层模型 id 不会改变,但是使用环境属性底层项目模型已经重新计算了 id,并且通过尝试两次呈现此视图而导致问题。
我跟你一样的问题,你是怎么解决的?