我对Swift还是很陌生-在完成在PDFView中显示文档的简单任务时遇到了一些麻烦。我不使用情节提要或IBOutlets等。为什么以下内容崩溃了？
我尝试引用外部链接，但它给了我同样的错误。 PDF存在于分发包目录中。
导入UIKit
导入PDFKit
类ViewController：UIViewController {
private var pdfView = PDFView()
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
let myNewView = PDFView(frame: CGRect(x: 10, y: 100, width: 500, height: 500))
// Add border to UIView
myNewView.layer.borderWidth=2
// Change UIView Border Color to Red
myNewView.layer.borderColor = UIColor.red.cgColor
guard let path = Bundle.main.path(forResource: "CV", ofType: "pdf") else { return }
let url = URL(fileURLWithPath: path)
let document = PDFDocument(url: url)
myNewView.document = document
// Add UIView as a Subview
self.view.addSubview(myNewView)
}
}
构建成功。但我得到以下。
2019-06-13 17：49：35.702174 + 0100 Appp [81235：19343962] *由于未捕获的异常“ CALayerInvalidGeometry”而终止应用程序，原因：“ CALayer位置包含NaN：[nan nan]”
*首先抛出调用堆栈：
（
0 CoreFoundation 0x00000001083446fb异常预处理+ 331
1个libobjc.A.dylib 0x0000000106250ac5 objc_exception_throw + 48
2 CoreFoundation 0x0000000108344555 + [NSException提高：格式：] + 197
3 QuartzCore 0x000000010b4072ae _ZN2CA5Layer12set_positionERKNS_4Vec2IdEEb + 140
4 QuartzCore 0x000000010b3f668b-[CALayer setPosition：] + 57
5 QuartzCore 0x000000010b3f6de3-[CALayer setFrame：] + 560
6 PDFKit 0x0000000107135097-[PDFPageLayerTile initWithFrame：forPageLayer：withRenderingTransform：tileContentsScale：generationID：] + 168
7 PDFKit 0x000000010713a805-[PDFPageLayer _updateTiles] + 3439
8 PDFKit 0x0000000107135d8e-[PDFPageLayer setNeedsTilesUpdate] + 87
9 PDFKit 0x000000010714a97d-[PDFPageView setNeedsTilesUpdate] + 48
10 PDFKit 0x000000010714c816-[PDFPageView setFrame：] + 334
11 PDFKit 0x000000010714311c-[PDFDocumentView createPageViewForPageAtIndex：] + 764
12 PDFKit 0x0000000107144326-[PDFDocumentView更新可见性] + 1726
13 PDFKit 0x00000001071b376f-[PDFView resizeDisplayView：] + 517
14 PDFKit 0x00000001071accdf-[PDFView layoutDocumentView] + 464
15 PDFKit 0x00000001071a836a-[PDFView setDocument：waitDuration：] + 1246
16附录0x000000010596c4d1 $ s7Appp14ViewControllerC11viewDidLoadyyF + 1441
17附录0x000000010596c7b4 $ s7Appp14ViewControllerC11viewDidLoadyyFTo + 36
18 UIKitCore 0x000000010d0ec43b-[UIViewController loadViewIfRequired] + 1183
19 UIKitCore 0x000000010d0ec868-[UIViewController视图] + 27
20 UIKitCore 0x000000010d724c33-[UIWindow addRootViewControllerViewIfPossible] + 122
21 UIKitCore 0x000000010d725327-[UIWindow setHidden：forced：] + 289
22 UIKitCore 0x000000010d737f86-[UIWindow makeKeyAndVisible] + 42
23 UIKitCore 0x000000010d6e7f1c-[UIApplication _callInitializationDelegatesForMainScene：transitionContext：] + 4555
24 UIKitCore 0x000000010d6ed0c6-[UIApplication _runWithMainScene：transitionContext：completion：] + 1617
25 UIKitCore 0x000000010cf326d6 __111-[__ UICanvasLifecycleMonitor_Compatability _scheduleFirstCommitForScene：transition：firstActivation：completion：] _ block_invoke + 904
26 UIKitCore 0x000000010cf3afce + [_ UICanvas _enqueuePostSettingUpdateTransactionBlock：] + 153
27 UIKitCore 0x000000010cf322ec-[__ UICanvasLifecycleMonitor_Compatability _scheduleFirstCommitForScene：transition：firstActivation：completion：] + 236
28 UIKitCore 0x000000010cf32c48-[__ UICanvasLifecycleMonitor_Compatability activateEventsOnly：withContext：completion：] + 1091
29 UIKitCore 0x000000010cf30fba __82-[_ UIApplicationCanvas _transitionLifecycleStateWithTransitionContext：completion：] _ block_invoke + 782
30 UIKitCore 0x000000010cf30c71-[_ UIApplicationCanvas _transitionLifecycleStateWithTransitionContext：completion：] + 433
31 UIKitCore 0x000000010cf359b6 __125-[_ UICanvasLifecycleSettingsDiffAction performActionsForCanvas：withUpdatedScene：settingsDiff：fromSettings：transitionContext：] _ block_invoke + 576
32 UIKitCore 0x000000010cf36610 _performActionsWithDelayForTransitionContext + 100
33 UIKitCore 0x000000010cf3571d-[_ UICanvasLifecycleSettingsDiffAction performActionsForCanvas：withUpdatedScene：settingsDiff：fromSettings：transitionContext：] + 223
34 UIKitCore 0x000000010cf3a6d0-[_ UICanvas场景：didUpdateWithDiff：transitionContext：完成：] + 392
35 UIKitCore 0x000000010d6eb9a8-[UIApplication工作区：didCreateScene：withTransitionContext：completion：] + 514
36 UIKitCore 0x000000010d2a2dfa-[UIApplicationSceneClientAgent场景：didInitializeWithEvent：完成：] + 361
37 FrontBoardServices 0x00000001135df125-[FBSSceneImpl _didCreateWithTransitionContext：completion：] + 448
38 FrontBoardServices 0x00000001135e8ed6 __56- [FBSWorkspace客户端：handleCreateScene：withCompletion：] _ block_invoke_2 + 283
39 FrontBoardServices 0x00000001135e8700 __40- [FBSWorkspace _performDelegateCallOut：] _ block_invoke + 53
40 libdispatch.dylib 0x00000001096d7db5 _dispatch_client_callout + 8
41 libdispatch.dylib 0x00000001096db2ba _dispatch_block_invoke_direct + 300
42 FrontBoardServices 0x000000011361a146 __FBSSERIALQUEUE_IS_CALLING_OUT_TO_A_BLOCK + 30
43 FrontBoardServices 0x0000000113619dfe-[FBSSerialQueue _performNext] + 451
44 FrontBoardServices 0x000000011361a393-[FBSSerialQueue _performNextFromRunLoopSource] + 42
45 CoreFoundation 0x00000001082abbe1 CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION + 17
46 CoreFoundation 0x00000001082ab463 __CFRunLoopDoSources0 + 243
47 CoreFoundation 0x00000001082a5b1f __CFRunLoopRun + 1231
48 CoreFoundation 0x00000001082a5302 CFRunLoopRunSpecific + 626
49 GraphicsServices 0x00000001107c62fe GSEventRunModal + 65
50个UIKitCore 0x000000010d6eeba2 UIApplicationMain + 140
51 Appp 0x000000010596f68b主+ 75
52 libdyld.dylib 0x000000010974c541开始+ 1
53 ??? 0x0000000000000001 0x0 + 1
）
libc ++ abi.dylib：以NSException类型的未捕获异常终止
（lldb）
最佳答案
如果将myNewView.document = document移到viewDidAppear:而不是viewDidLoad，则文档将加载而不会出现问题。
不幸的是，在12.1和12.2之间对iOS进行了更改，因此有必要。