我正在使用 Xcode 6 开发 iOS 应用程序。

当我使用 UIAlertController 时，它在 iPhone 6 模拟器上可以正常运行，但在 iPad 模拟器上会崩溃。

我的问题是点击“分享”时，它可能会崩溃。 我该如何解决？

这是我的代码:

override func tableView(tableView: UITableView, editActionsForRowAtIndexPath indexPath: NSIndexPath) -> [AnyObject] {

    var shareAction = UITableViewRowAction(style: UITableViewRowActionStyle.Default, title: "Share", handler: { (action:UITableViewRowAction!, indexPath:NSIndexPath!) -> Void in

        let shareMenu = UIAlertController(title: nil, message: "Share using", preferredStyle: .ActionSheet)
        let twitterAction = UIAlertAction(title: "Twitter", style: UIAlertActionStyle.Default, handler: nil)
        let facebookAction = UIAlertAction(title: "Facebook", style: UIAlertActionStyle.Default, handler: nil)
        let emailAction = UIAlertAction(title: "Email", style: UIAlertActionStyle.Default, handler: nil)
        let cancelAction = UIAlertAction(title: "Cancel", style: UIAlertActionStyle.Cancel, handler: nil)

        shareMenu.addAction(twitterAction)
        shareMenu.addAction(facebookAction)
        shareMenu.addAction(emailAction)
        shareMenu.addAction(cancelAction)

        self.presentViewController(shareMenu, animated: true, completion: nil)
        }
    )

Xcode 显示此消息:

******Terminating app due to uncaught exception 'NSGenericException', reason: 'Your application has presented a UIAlertController (<UIAlertController: 0xaf71c80>) of style UIAlertControllerStyleActionSheet. The modalPresentationStyle of a UIAlertController with this style is UIModalPresentationPopover. You must provide location information for this popover through the alert controller's popoverPresentationController. You must provide either a sourceView and sourceRect or a barButtonItem.  If this information is not known when you[![enter image description here][1]][1] present the alert controller, you may provide it in the UIPopoverPresentationControllerDelegate method -prepareForPopoverPresentation.'
*** First throw call stack:
(
    0   CoreFoundation                      0x0023c746 __exceptionPreprocess + 182
    1   libobjc.A.dylib                     0x01c7aa97 objc_exception_throw + 44
    2   UIKit                               0x012c4062 -[UIPopoverPresentationController presentationTransitionWillBegin] + 3086
    3   UIKit                               0x00bda174 __71-[UIPresentationController _initViewHierarchyForPresentationSuperview:]_block_invoke + 1549
    4   UIKit                               0x00bd8247 __56-[UIPresentationController runTransitionForCurrentState]_block_invoke + 198
    5   UIKit                               0x00c0d31b __40+[UIViewController _scheduleTransition:]_block_invoke + 18
    6   UIKit                               0x00ac6862 ___afterCACommitHandler_block_invoke + 15
    7   UIKit                               0x00ac680d _applyBlockToCFArrayCopiedToStack + 415
    8   UIKit                               0x00ac6622 _afterCACommitHandler + 549
    9   CoreFoundation                      0x0015d86e __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 30
    10  CoreFoundation                      0x0015d7b0 __CFRunLoopDoObservers + 400
    11  CoreFoundation                      0x001531ea __CFRunLoopRun + 1226
    12  CoreFoundation                      0x00152a5b CFRunLoopRunSpecific + 443
    13  CoreFoundation                      0x0015288b CFRunLoopRunInMode + 123
    14  GraphicsServices                    0x047b82c9 GSEventRunModal + 192
    15  GraphicsServices                    0x047b8106 GSEventRun + 104
    16  UIKit                               0x00a9c106 UIApplicationMain + 1526
    17  Mars I                              0x0001c724 main + 180
    18  libdyld.dylib                       0x02392ac9 start + 1
    19  ???                                 0x00000001 0x0 + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException******

最佳答案

要使其独立于设备，请按照下面的代码片段所示使用它。此代码将在 iPhone/小型设备上为 popoverPresentationController 返回 nil，因此您可以安全地在通用项目中使用它。

if let popoverPresentationController = shareMenu.popoverPresentationController {
    popoverPresentationController.sourceView = self.view
    popoverPresentationController.sourceRect = sender.bounds
}
self.presentViewController(shareMenu, animated: true, completion: nil)

关于ios - UIAlertController 崩溃 (iPad)，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/31577140/