ios - Objective-c UIDocumentInteractionController 加载灰屏

Question

我正在尝试像这样预览 UIDocumentInteractionController:

NSString* filePath = [[NSBundle mainBundle] pathForResource:@"FLW-0032 Design Sketches" ofType:@"pdf"];

_previewItemURL = [NSURL URLWithString:filePath];

UIDocumentInteractionController *documentInteractionController =[UIDocumentInteractionController interactionControllerWithURL:_previewItemURL];
                        
documentInteractionController.delegate = self;

[documentInteractionController presentPreviewAnimated:YES];

我得到的只是带有文件名的灰色屏幕。文件大小为5.5MB

我做错了什么？

这是我的委托(delegate)方法:

- (UIViewController *) documentInteractionControllerViewControllerForPreview: (UIDocumentInteractionController *) controller {
    return self.navigationController;
}

我在我的控制台日志中看到了这个

[Snapshotting] Snapshotting a view (0x108c80800,_UIButtonBarStackView) that has not been rendered at least once requires afterScreenUpdates:YES. 2018-03-07 20:39:16.169613-0500SchedulingiPadApplication[417:61893] [default] Couldn't issue fileextension for url:file:///var/containers/Bundle/Application/23540D89-0841-4F12-A6A4-A2840D4076F4/SchedulingiPadApplication.app/FLW-0032%20Design%20Sketches.pdf

PreviewItem

当我呈现 documentInteractionController 时会发生这种情况

Answer 1

您需要使用 NSURL fileURLWithPath:，而不是 URLWithString:。

更好的是，使用 NSBundle URLForResource:withExtension: 直接获取 NSURL。