iPad上的ActionSheet崩溃（摄像头按钮）

Question

我的行动表有些问题。在iPhone上它工作正常，但在iPad上它只是崩溃了。

我有一个按钮来显示相机，但我不能在iPad上正确操作。

代码：

class pictureViewController: UIViewController, UIImagePickerControllerDelegate, UINavigationControllerDelegate, UITextViewDelegate {
    @IBOutlet weak var picture: UIImageView!
    override func viewDidLoad() {
    }

    @IBAction func choosePictureAction(sender: AnyObject) {
        let alertPictureFrom = UIAlertController(title: "De dónde sacar la foto?", message: "", preferredStyle: UIAlertControllerStyle.ActionSheet)
        presentViewController(alertPictureFrom, animated: true, completion: nil)
        alertPictureFrom.addAction(UIAlertAction(title: "Cámara", style: .Default, handler: {action in
            let picker = UIImagePickerController()
            picker.sourceType = .Camera
            picker.delegate = self
            picker.allowsEditing = true
            self.presentViewController(picker, animated: true, completion: nil)
        }))

        alertPictureFrom.addAction(UIAlertAction(title: "Galería", style: .Default, handler: {action in
            let picker = UIImagePickerController()
            picker.sourceType = .PhotoLibrary
            picker.delegate = self
            picker.allowsEditing = true
            self.presentViewController(picker, animated: true, completion: nil)
        }))
    }

    func imagePickerController(picker: UIImagePickerController, didFinishPickingImage image: UIImage, editingInfo: [String : AnyObject]?) {
        picture.image = image
        picker.dismissViewControllerAnimated(true, completion: nil)
    }

}

您的应用程序提供了UIAlertController（）风格的UIAlertControlllerStyleActionSheet。具有此样式的UIAlertController的modalPresentationStyle是UIModalPresentationPopover。您必须通过警报控制器的popoverPresentationController提供此弹出窗口的位置信息。您必须提供源视图和源Rect或barButtonItem。如果在显示警报控制器时不知道此信息，则可以在UIPopoverPresentationControlller委托方法-preareForPopoverPresations中提供。

Answer 1

由于UIActionSheet导致的错误发生

ipad不支持UIActionSheet。对于iphone，在iphone UIActionsheet中无事可做对于IPAD，UIActionsheet可以在另一个视图中打开，如

UIActionSheetObjects.showFromRect(CGRectMake(150, 0, 300,200 ) ,inView:self.view, animated:YES)

它会为你工作。。。

Answer 2

尝试（在UIButton的情况下）：

picker.popoverPresentationController?.sourceView = testButton
picker.popoverPresentationController?.sourceRect = testButton.bounds
picker.popoverPresentationController?.permittedArrowDirections = UIPopoverArrowDirection.Right.bounds

Answer 3

正如错误消息所说：“您必须通过popoverPresentationController

这将允许UIKit知道从何处显示popover，然后您将获得一个可爱的行为，popover显示在您指定的元素上。

例如：

alertPictureFrom.popoverPresentationController?.sourceRect = CGRect(x: 0.0, y: 0.0, width: 1.0, height: 1.0)
alertPictureFrom.popoverPresentationController?.sourceView = self.view

现在，该示例完全用于演示目的，您需要为popover找出sourceView和sourceRect。

参考文件：

• popoverPresentationController