iOS game crashes after pressing Share button only on iPad

问题

My iOS game crashes after the share button is pressed. This button then gives the users the option to post/send a pre-written text line and a link to the app to Twitter, FB, Mail, Messages,etc. I am able to replicate the crash on the all iPad simulators running iOS 8.2.

Here is the symbolicated crash report: https://www.dropbox.com/s/yyo4ouniegt6s0e/dotSports.crash?dl=0

In addition: This is from the output box in Xcode when taking the actions to produce the crash.

*** Terminating app due to uncaught exception 'NSGenericException', reason: 'UIPopoverPresentationController (<_UIAlertControllerActionSheetRegularPresentationController: 0x7a863100>) should have a non-nil sourceView or barButtonItem set before the presentation occurs.'
*** First throw call stack:
(
    0   CoreFoundation                      0x04980466 __exceptionPreprocess + 182
    1   libobjc.A.dylib                     0x03caea97 objc_exception_throw + 44
    2   UIKit                               0x02564517 -[UIPopoverPresentationController presentationTransitionWillBegin] + 3086
    3   UIKit                               0x01e63f48 __71-[UIPresentationController _initViewHierarchyForPresentationSuperview:]_block_invoke + 1666
    4   UIKit                               0x01e624eb __56-[UIPresentationController runTransitionForCurrentState]_block_invoke + 186
    5   UIKit                               0x01e9642b __40+[UIViewController _scheduleTransition:]_block_invoke + 18
    6   UIKit                               0x01d5b946 ___afterCACommitHandler_block_invoke + 15
    7   UIKit                               0x01d5b8f1 _applyBlockToCFArrayCopiedToStack + 415
    8   UIKit                               0x01d5b706 _afterCACommitHandler + 545
    9   CoreFoundation                      0x048a318e __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 30
    10  CoreFoundation                      0x048a30d0 __CFRunLoopDoObservers + 400
    11  CoreFoundation                      0x04898b0a __CFRunLoopRun + 1226
    12  CoreFoundation                      0x0489837b CFRunLoopRunSpecific + 443
    13  CoreFoundation                      0x048981ab CFRunLoopRunInMode + 123
    14  GraphicsServices                    0x0524d2c1 GSEventRunModal + 192
    15  GraphicsServices                    0x0524d0fe GSEventRun + 104
    16  UIKit                               0x01d319b6 UIApplicationMain + 1526
    17  Gem Dots copy                       0x00213896 main + 134
    18  libdyld.dylib                       0x04365ac9 start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb)  

Here is the code that it crashes at:

#import <UIKit/UIKit.h>

int main(int argc, char *argv[]) {

    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
    int retVal = UIApplicationMain(argc, argv, nil, @"AppController");
    [pool release];
    return retVal;
}

Here is the code for the share button:

-(void) displayShare:(NSString*)strText imageIdx:(int)nIdx URL:(NSString*)strURL
{
    UIActivityViewController *activityView;

    if(nIdx >= 0)
    {
        NSString* str = [NSString stringWithFormat:@"new-arc-%d-ipad.png", nIdx+1];
        UIImage* image = [UIImage imageNamed:str];
        activityView = [[UIActivityViewController alloc] initWithActivityItems:@[strText, image, [NSURL URLWithString:strURL]] applicationActivities:nil];
    }
    else
        activityView = [[UIActivityViewController alloc] initWithActivityItems:@[strText, [NSURL URLWithString:strURL]] applicationActivities:nil];

    activityView.excludedActivityTypes = @[UIActivityTypeCopyToPasteboard, UIActivityTypeAssignToContact, UIActivityTypeSaveToCameraRoll, UIActivityTypePrint];

   // [viewController presentViewController:activityView animated:YES completion:nil];
    [window.rootViewController presentViewController:activityView animated:YES completion:nil];

    [activityView setCompletionHandler:^(NSString *activityType, BOOL completed) {
        NSLog(@"completed dialog - activity: %@ - finished flag: %d", activityType, completed);

        if(completed)
        {
            if([activityType isEqualToString: @"com.apple.UIKit.activity.PostToFacebook"] )
            {
                g_bArchiveMark[19] = true;
                AppSettings::setArchieveInfo(19);
            }
            else if([activityType isEqualToString: @"com.apple.UIKit.activity.PostToTwitter"] )
            {
                g_bArchiveMark[20] = true;
                AppSettings::setArchieveInfo(20);

            }
        }
    }];


}

Any thoughts to what might be causing the crash or how to remedy the crash?

Thank you!

回答1:

You're using a UIAlertController to display your share buttons without the inclusion of a UIPopoverPresentationController. You must use a UIPopoverPresentationController when your app is running on an iPad. Apple Docs on UIPopoverPresentationController.

For example:

-(IBAction)myButton:(id)sender {
    UIAlertController *shareController=   [UIAlertController
                                alertControllerWithTitle:nil
                                message:nil
                                preferredStyle:UIAlertControllerStyleActionSheet];
    UIAlertAction *shareServiceButton = [UIAlertAction
                                   actionWithTitle:@"Share Service"
                                   style:UIAlertActionStyleDefault
                                   handler:^(UIAlertAction *action)
                                   {
                                       // Share something
                                   }];
    [shareController addAction:shareServiceButton];

    // User on iPad
    UIPopoverPresentationController *popoverController;
    popoverController = shareController.popoverPresentationController;
    popoverController.sourceView = self.view;
    popoverController.sourceRect = self.myButton.frame;
    popoverController.permittedArrowDirections = UIPopoverArrowDirectionAny;

    [self presentViewController:shareController animated:YES completion:nil];
}

来源：https://stackoverflow.com/questions/29997369/ios-game-crashes-after-pressing-share-button-only-on-ipad