UIAlertController崩溃了（iPad）

Question

我正在使用 Xcode 6 开发 iOS 应用程序。

当我使用 UIAlertController 时，在 iPhone 6 模拟器上可以正常工作，但在 iPad 模拟器上崩溃了。

我的问题是，在点击“分享”时，它可能会崩溃。我该怎么解决？

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显示了这条消息：

******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 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******

- user5122712

---

苹果表示，如果您想呈现任何视图控制器，并且它的类型为AlertViewController，则应该将其呈现在弹出窗口中，而不是独立的视图，因为这涉及到用户体验的问题。 - Ruchish Shah

Answer 1

为了保持设备的独立性，建议按照下面代码片段所示的方式使用它。此代码将在 iPhone / 紧凑尺寸设备上返回 nil，因此您可以在通用项目中安全地使用它。

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

- Karoly Nyisztor

---

刚在iOS10上遇到了这个问题，不认为它已经修复。 - deloki

实际上，您不需要执行if let检查，因为如果popoverPresentationController为nil，则不会设置任何内容。 - Harish

应该使用sender而不是self.view来显示正确的箭头方向，.sourceView。 - Adam Smaka

没错，只需要 popoverPresentationController?.sourceView = self.view 和 popoverPresentationController?.sourceRect = sender.bounds 就足够了。 - Harry Bloom

在这种情况下，“sender”到底是什么？ 它是执行操作的视图吗？ - Ichor de Dionysos

是的，发送者是触发操作的UIControl或UIView。 - Karoly Nyisztor

Answer 2

尝试这段代码：

shareMenu.popoverPresentationController.sourceView = self.view
shareMenu.popoverPresentationController.sourceRect = CGRectMake(self.view.bounds.size.width / 2.0, self.view.bounds.size.height / 2.0, 1.0, 1.0)

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

- isaced

---

你能解释一下 CGRectMake(self.view.bounds.size.width / 2.0, self.view.bounds.size.height / 2.0, 1.0, 1.0) 的意思吗？ - Cerlin

@CerlinBoss 这个定义了一个在视图中心的1像素正方形，用于指示菜单箭头的指向。 - Cœur

Answer 3

Swift 4

popoverPresentationController.permittedArrowDirections = .init(rawValue: 0)
popoverPresentationController.sourceView = self.view
popoverPresentationController.sourceRect = CGRect(x: self.view.bounds.midX, y: self.view.bounds.midY, width: 0, height: 0)

- kurtanamo

Answer 4

参考：在Swift中iPad上的ActionSheet Popover

创建popoverController：

let alertController = UIAlertController(title: nil, message: "Alert message.", preferredStyle: .actionSheet)
self.present(alertController, animated: true, completion: nil)

如果您想要显示带有指示器视图的警告框，应该：

if let popoverController = alertController.popoverPresentationController {
    popoverController.barButtonItem = sender
}

带指示器

在中心显示警告：

if let popoverController = alertController.popoverPresentationController {
  popoverController.sourceView = self.view
  popoverController.sourceRect = CGRect(x: self.view.bounds.midX, y: self.view.bounds.midY, width: 0, height: 0) 
}

无指示器的居中：

if let popoverController = alertController.popoverPresentationController {
  popoverController.sourceView = self.view
  popoverController.sourceRect = CGRect(x: self.view.bounds.midX, y: self.view.bounds.midY, width: 0, height: 0)
  popoverController.permittedArrowDirections = []
}

- yuelong qin

Answer 5

我也遇到了同样的问题，最终找到了解决方案。这是我为Objective-C提供的解决方案：

UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"Select you option:"
                                                                         message:nil
                                                                  preferredStyle:UIAlertControllerStyleActionSheet];

UIAlertAction *action = [UIAlertAction actionWithTitle:@“share”
                                                     style:UIAlertActionStyleDefault
                                                   handler:^(UIAlertAction *action) {
                                                       // do other things
                                                   }];
[alertController addAction:action];

UIAlertAction *cancelAction = [UIAlertAction actionWithTitle:@"Cancel"
                                                       style:UIAlertActionStyleCancel
                                                     handler:^(UIAlertAction *action) {
                                                     }];
[alertController addAction:cancelAction];

// Remove arrow from action sheet.
[alertController.popoverPresentationController setPermittedArrowDirections:0];

//For set action sheet to middle of view.
CGRect rect = self.view.frame;
rect.origin.x = self.view.frame.size.width / 20;
rect.origin.y = self.view.frame.size.height / 20;
alertController.popoverPresentationController.sourceView = self.view;
alertController.popoverPresentationController.sourceRect = rect;

[self presentViewController:alertController animated:YES completion:nil];

- Mayuri R Talaviya

---

好奇为什么我们要除以20。我尝试了2.0，但它放在右下角了。几何方面还有一些不清楚的地方。 - SpaceTrucker

Swift 4 去除箭头： popoverPresentationController.permittedArrowDirections = .init(rawValue: 0) - kurtanamo

Answer 6

我使用这个方便的扩展来创建不会崩溃的操作表。

extension UIAlertController {

    class func actionSheetWith(title: String?, message: String?, sourceView: UIView?, sourceFrame: CGRect?) -> UIAlertController {
        let actionController = UIAlertController(title: title, message: message, preferredStyle: .actionSheet)
        if actionController.responds(to: #selector(getter: popoverPresentationController)) {
            actionController.popoverPresentationController?.sourceView = sourceView ?? StoryboardHelper.tabBarControllerTopController()?.view
            actionController.popoverPresentationController?.sourceRect = sourceFrame ?? CGRect(x: 0, y: 0, width: 0, height: 0)
        }
        return actionController
    }

}

- Jose Rosales

Answer 7

我使用这段代码，非常简单易懂，也许我可以帮助任何人。

//if iPhone
    if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone) {
        [self presentViewController:actionSheet animated:YES completion:nil];
    }
    //if iPad
    else {
        // Change Rect to position Popover
        UIPopoverController *popup = [[UIPopoverController alloc] initWithContentViewController:actionSheet];
        [popup presentPopoverFromRect:CGRectMake(self.view.frame.size.width/2, self.view.frame.size.height/4, 0, 0)inView:self.view permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES];
    }

- Genevios

Answer 8

我发现这个链接很有用，对我起作用了

https://medium.com/@nickmeehan/actionsheet-popover-on-ipad-in-swift-5768dfa82094

我对以下内容进行了微小的更改，以调整对齐方式。

if let popoverPresentationController = alert.popoverPresentationController {
        popoverPresentationController.sourceView = self.view
        popoverPresentationController.sourceRect = CGRect(x: self.view.bounds.midX, y: self.view.bounds.size.height * 0.85, width: 0, height: 0)
        popoverPresentationController.permittedArrowDirections = []
    }

- mustaq

Answer 9

迅捷 3

shareMenu.popoverPresentationController?.sourceView = self.view
shareMenu.popoverPresentationController?.sourceRect = 
    CGRect(x: view.bounds.size.width, 
           y: view.bounds.size.height-80, 
           width: 1.0, height: 1.0)

源矩形是您想要显示弹出视图的点。

- sohail059

Answer 10

如果您不需要将警报显示为弹出窗口，可以在初始化AlertViewController时使用UIAlertController.Style.alert作为首选样式。

let shareMenu = UIAlertController(title: nil, message: "Share using", preferredStyle: .alert)

- Olexa Boyko