Strange issue with UIDocumentInteractionController

Question

I don't know what wrong with this code but everytime when I run the app, after the Menu is shown, the app crash.

NSString * path = [[NSBundle mainBundle] pathForResource:@"tung" ofType:@"doc"];

UIDocumentInteractionController *docController = [UIDocumentInteractionController interactionControllerWithURL:[NSURL fileURLWithPath:path]];

docController.delegate = self;

//[docController presentPreviewAnimated:YES];

CGRect rect = CGRectMake(0, 0, 300, 300);
[docController presentOptionsMenuFromRect:rect inView:self.view animated:YES];

Error I got:

*** Terminating app due to uncaught exception 'NSGenericException', reason: '-[UIPopoverController dealloc] reached while popover is still visible.'

What should I do now ?

Answer 1

To preview a document via a "throwaway" UIDocumentInteractionController you should retain it after interactionControllerWithURL and autorelease it in the UIDocumentInteractionControllerDelegate method documentInteractionControllerDidDismissOptionsMenu. As remarked by David Liu, releasing it will crash. But autoreleasing works. I have checked that dealloc is actually called.

The following code should work:

- (void)previewDocumentWithURL:(NSURL*)url
{
    UIDocumentInteractionController* preview = [UIDocumentInteractionController interactionControllerWithURL:url];
    preview.delegate = self;
    [preview presentPreviewAnimated:YES];
    [preview retain];
}
- (void)documentInteractionControllerDidEndPreview:(UIDocumentInteractionController *)controller
{
    [controller autorelease];
}