Question

在iOS 8.0中，Apple引入了UIAlertController来替换UIActionSheet。不幸的是，Apple没有添加任何有关如何呈现它的信息。我在hayaGeek的博客上发现了entry，但它似乎不能在iPad上运行。这种观点完全错位了：

错位： Misplaced image

正确： enter image description here

我使用以下代码在界面上显示它：

    let alert = UIAlertController()
    // setting buttons
    self.presentModalViewController(alert, animated: true)

有没有其他方法可以为iPad添加它？或者苹果只是忘了iPad，还是没有实现？

Answer 1

您可以使用UIAlertController从弹出窗口中展示UIPopoverPresentationController。

在Obj-C中：

UIViewController *self; // code assumes you're in a view controller
UIButton *button; // the button you want to show the popup sheet from

UIAlertController *alertController;
UIAlertAction *destroyAction;
UIAlertAction *otherAction;

alertController = [UIAlertController alertControllerWithTitle:nil
                                                      message:nil
                           preferredStyle:UIAlertControllerStyleActionSheet];
destroyAction = [UIAlertAction actionWithTitle:@"Remove All Data"
                                         style:UIAlertActionStyleDestructive
                                       handler:^(UIAlertAction *action) {
                                           // do destructive stuff here
                                       }];
otherAction = [UIAlertAction actionWithTitle:@"Blah"
                                       style:UIAlertActionStyleDefault
                                     handler:^(UIAlertAction *action) {
                                         // do something here
                                     }];
// note: you can control the order buttons are shown, unlike UIActionSheet
[alertController addAction:destroyAction];
[alertController addAction:otherAction];
[alertController setModalPresentationStyle:UIModalPresentationPopover];

UIPopoverPresentationController *popPresenter = [alertController 
                                              popoverPresentationController];
popPresenter.sourceView = button;
popPresenter.sourceRect = button.bounds;
[self presentViewController:alertController animated:YES completion:nil];

编辑Swift 4.2，虽然有很多博客可用，但它可以节省您的时间去搜索它们。

 if let popoverController = yourAlert.popoverPresentationController {
                popoverController.sourceView = self.view //to set the source of your alert
                popoverController.sourceRect = CGRect(x: self.view.bounds.midX, y: self.view.bounds.midY, width: 0, height: 0) // you can set this as per your requirement.
                popoverController.permittedArrowDirections = [] //to hide the arrow of any particular direction
            }

Answer 2

在iPad上，警报将使用新的 UIPopoverPresentationController 显示为弹出窗口，它要求您使用sourceView和sourceRect或barButtonItem指定弹出窗口的定位点

barButtonItem
sourceView
sourceRect

为了指定锚点，您需要获取对UIAlertController的UIPopoverPresentationController的引用，并设置其中一个属性，如下所示：

alertController.popoverPresentationController.barButtonItem = button;

示例代码：

UIAlertAction *actionDelete = nil;
UIAlertAction *actionCancel = nil;

// create action sheet
UIAlertController *alertController = [UIAlertController
                                      alertControllerWithTitle:actionTitle message:nil
                                      preferredStyle:UIAlertControllerStyleActionSheet];

// Delete Button
actionDelete = [UIAlertAction
                actionWithTitle:NSLocalizedString(@"IDS_LABEL_DELETE", nil)
                style:UIAlertActionStyleDestructive handler:^(UIAlertAction *action) {

                    // Delete
                    // [self deleteFileAtCurrentIndexPath];
                }];

// Cancel Button
actionCancel = [UIAlertAction
                actionWithTitle:NSLocalizedString(@"IDS_LABEL_CANCEL", nil)
                style:UIAlertActionStyleCancel handler:^(UIAlertAction *action) {
                    // cancel
                    // Cancel code
                }];

// Add Cancel action
[alertController addAction:actionCancel];
[alertController addAction:actionDelete];

// show action sheet
alertController.popoverPresentationController.barButtonItem = button;
alertController.popoverPresentationController.sourceView = self.view;

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

Answer 3

在Swift 2中，你想做类似的事情，以便在iPhone和iPad上正确显示它：

func confirmAndDelete(sender: AnyObject) {
    guard let button = sender as? UIView else {
        return
    }

    let alert = UIAlertController(title: NSLocalizedString("Delete Contact?", comment: ""), message: NSLocalizedString("This action will delete all downloaded audio files.", comment: ""), preferredStyle: .ActionSheet)
    alert.modalPresentationStyle = .Popover

    let action = UIAlertAction(title: NSLocalizedString("Delete", comment: ""), style: .Destructive) { action in
        EarPlaySDK.deleteAllResources()
    }
    let cancel = UIAlertAction(title: NSLocalizedString("Cancel", comment: ""), style: .Cancel) { action in

    }
    alert.addAction(cancel)
    alert.addAction(action)

    if let presenter = alert.popoverPresentationController {
        presenter.sourceView = button
        presenter.sourceRect = button.bounds
    }
    presentViewController(alert, animated: true, completion: nil)
}

如果您没有设置演示者，则最终会在-[UIPopoverPresentationController presentationTransitionWillBegin]的iPad上发布例外消息，并显示以下消息：

致命异常：NSGenericException 您的应用程序提供了样式UIAlertControllerStyleActionSheet的UIAlertController（＆lt; UIAlertController：0x17858a00＆gt;）。具有此样式的UIAlertController的modalPresentationStyle是UIModalPresentationPopover。您必须通过警报控制器的popoverPresentationController为此弹出窗口提供位置信息。您必须提供sourceView和sourceRect或barButtonItem。如果在显示警报控制器时不知道此信息，您可以在UIPopoverPresentationControllerDelegate方法-prepareForPopoverPresentation中提供它。

Answer 4

Swift 3.0及更高版本的更新

    let actionSheetController: UIAlertController = UIAlertController(title: "SomeTitle", message: nil, preferredStyle: .actionSheet)

    let editAction: UIAlertAction = UIAlertAction(title: "Edit Details", style: .default) { action -> Void in

        print("Edit Details")
    }

    let deleteAction: UIAlertAction = UIAlertAction(title: "Delete Item", style: .default) { action -> Void in

        print("Delete Item")
    }

    let cancelAction: UIAlertAction = UIAlertAction(title: "Cancel", style: .cancel) { action -> Void in }

    actionSheetController.addAction(editAction)
    actionSheetController.addAction(deleteAction)
    actionSheetController.addAction(cancelAction)

//        present(actionSheetController, animated: true, completion: nil)   // doesn't work for iPad

    actionSheetController.popoverPresentationController?.sourceView = yourSourceViewName // works for both iPhone & iPad

    present(actionSheetController, animated: true) {
        print("option menu presented")
    }

Answer 5

2018年更新

由于这个原因我只是拒绝了一个应用程序，而且很快就解决了从使用操作表到警报的过程。

工作了一个魅力，并通过了App Store测试人员。

对于每个人来说可能不是一个合适的答案，但我希望这能帮助你们中的一些人迅速摆脱困境。

Answer 6

这是一个快速解决方案：

NSString *text = self.contentTextView.text;
NSArray *items = @[text];

UIActivityViewController *activity = [[UIActivityViewController alloc]
                                      initWithActivityItems:items
                                      applicationActivities:nil];

activity.excludedActivityTypes = @[UIActivityTypePostToWeibo];

if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPad) {
    //activity.popoverPresentationController.sourceView = shareButtonBarItem;

    activity.popoverPresentationController.barButtonItem = shareButtonBarItem;

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

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

Answer 7

迅速达到4以上

我创建了一个扩展程序

extension UIViewController {
  public func addActionSheetForiPad(actionSheet: UIAlertController) {
    if let popoverPresentationController = actionSheet.popoverPresentationController {
      popoverPresentationController.sourceView = self.view
      popoverPresentationController.sourceRect = CGRect(x: self.view.bounds.midX, y: self.view.bounds.midY, width: 0, height: 0)
      popoverPresentationController.permittedArrowDirections = []
    }
  }
}

使用方法：

let actionSheetVC = UIAlertController(title: "Title", message: nil, preferredStyle: .actionSheet)
addActionSheetForIpad(actionSheet: actionSheetVC)
present(actionSheetVC, animated: true, completion: nil)

Answer 8

    if let popoverController = alertController.popoverPresentationController {
        popoverController.barButtonItem = navigationItem.rightBarButtonItem
    }

对我来说，我只需要添加这一行

Answer 9

迅捷4.2 您可以使用这样的条件：

let alert = UIAlertController(title: nil, message: nil, preferredStyle: UIDevice.current.userInterfaceIdiom == .pad ? .alert : .actionSheet)

Answer 10

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

只需在展示您的uiactionsheet之前添加以上代码

Answer 11

iphone 和 ipad 都可以使用

func showImagePicker() {
    var alertStyle = UIAlertController.Style.actionSheet
    if (UIDevice.current.userInterfaceIdiom == .pad) {
      alertStyle = UIAlertController.Style.alert
    }
    let alert = UIAlertController(title: "", message: "Upload Attachment", preferredStyle: alertStyle)
    alert.addAction(UIAlertAction(title: "Choose from gallery", style: .default , handler:{ (UIAlertAction) in
        self.pickPhoto(sourceType: .photoLibrary)
    }))
    alert.addAction(UIAlertAction(title: "Take Photo", style: .default, handler:{ (UIAlertAction) in
        self.pickPhoto(sourceType: .camera)
    }))
    alert.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler:{ (UIAlertAction) in
    }))
    present(alert, animated: true, completion: nil)
}

使用iOS 8在iPad上正确呈现UIAlertController

11 个答案:

在Obj-C中：