如何在iPad中使用UIImagePickerController？

Question

嗨，我正在开发通用应用程序（iPhone / iPad）。 一个功能是我必须从相册中选择一张照片并在UIImageView上显示。

现在的问题是它在iPhone上运行良好但是当我尝试打开相册时它会崩溃。 我在行动表委托中的代码是这样的：

- (void) actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex
{
    if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad){
        if ( ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]))

        {   
            if (buttonIndex == 0)
            {
                [self lockAllImagesOnTheScreen];
                imagePicker.sourceType=UIImagePickerControllerSourceTypeCamera;
                [self presentModalViewController:imagePicker animated:YES];
            }
            if (buttonIndex == 1)
            {
                [self lockAllImagesOnTheScreen];

                imagePicker.sourceType= UIImagePickerControllerSourceTypePhotoLibrary;
                [self presentModalViewController:imagePicker animated:YES];
            }

        }
        else {

            if (buttonIndex == 0)
            {
                [self lockAllImagesOnTheScreen];
                imagePicker.sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;
                imagePicker.sourceType= UIImagePickerControllerSourceTypePhotoLibrary;
                [self presentModalViewController:imagePicker animated:YES];
            }
        }



    }

    else{
        if ( ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]))

        {   
            if (buttonIndex == 0)
            {
                [self lockAllImagesOnTheScreen];
                imagePicker.sourceType=UIImagePickerControllerSourceTypeCamera;
                [self presentModalViewController:imagePicker animated:YES];
            }
            if (buttonIndex == 1)
            {
                [self lockAllImagesOnTheScreen];

                imagePicker.sourceType= UIImagePickerControllerSourceTypePhotoLibrary;
                [self presentModalViewController:imagePicker animated:YES];
            }

        }
        else {

            if (buttonIndex == 0)
            {
                [self lockAllImagesOnTheScreen];
                imagePicker.sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;
                imagePicker.sourceType= UIImagePickerControllerSourceTypePhotoLibrary;
                [self presentModalViewController:imagePicker animated:YES];
            }
        }


    }


}

任何身体可以帮助我吗？ 我已经检查了stackOverflow并且也搜索了它但是徒劳无功。

Answer 1

UIImagePickerController 必须在iPad上显示UIPopoverController 。

if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPad) {
    UIPopoverController *popover = [[UIPopoverController alloc] initWithContentViewController:picker];
    [popover presentPopoverFromRect:self.selectedImageView.bounds inView:self.selectedImageView permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES];
    self.popOver = popover;
} else {
    [self presentModalViewController:picker animated:YES];
}

编辑 ：为UIPopoverController添加一个强大的属性：

@property (nonatomic, strong) UIPopoverController *popOver;

应该在委托方法中解除popover：

-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info 

-(void)imagePickerControllerDidCancel:(UIImagePickerController *)picker 

Answer 2

在这里，我向您展示SWIFT方式：

import UIKit
class StoreItemViewController: UIViewController, UIImagePickerControllerDelegate, UINavigationControllerDelegate
{
    @IBOutlet weak var button: UIButton!
    @IBOutlet weak var productImage: UIImageView!
    var popOver:UIPopoverController?

    @IBAction func buttonSelected(sender:UIButton)
    {
        if UIImagePickerController.isSourceTypeAvailable(UIImagePickerControllerSourceType.SavedPhotosAlbum)
        {
            var imagePickerController = UIImagePickerController()
            imagePickerController.delegate = self
            imagePickerController.sourceType = UIImagePickerControllerSourceType.SavedPhotosAlbum
            imagePickerController.allowsEditing = false

            if UIDevice.currentDevice().userInterfaceIdiom == UIUserInterfaceIdiom.Pad
            {
                self.popOver = UIPopoverController(contentViewController: imagePickerController)
                self.popOver?.presentPopoverFromRect(self.productImage.bounds, inView: self.productImage, permittedArrowDirections: UIPopoverArrowDirection.Any, animated: true)      
            }
            else
            {
                self.presentViewController(imagePickerController, animated: true, completion: { imageP in

                })
            } 
        }
    }

    func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [NSObject : AnyObject]) {
         //do anything with the image
        let selectedImage = info[UIImagePickerControllerOriginalImage] as UIImage

        //closing the popup
        popOver?.dismissPopoverAnimated(true)

    }

    func imagePickerControllerDidCancel(picker: UIImagePickerController) 
    {
         println("cancel")

       //closing the popup
       popOver?.dismissPopoverAnimated(true)
    }
}

Answer 3

Apple医生说

“通过调用presentViewController：animated：completion：当前活动视图控制器的方法来呈现用户界面，将配置的图像选择器控制器作为新的视图控制器传递。在iPad上，使用弹出窗口显示用户界面。这样做只有效如果图像选择器控制器的sourceType属性设置为UIImagePickerControllerSourceTypeCamera。“

这说明与其表现完全相反？！？ 你不能现在UIImagePickerControllerSourceTypeCamera从酥料饼，你不能现在UIImagePickerControllerSourceTypePhotoLibrary和UIImagePickerControllerSourceTypeSavedPhotosAlbum模态。

奇怪...

Answer 4

POST iOS 8：尝试添加popOver控制器

[[NSOperationQueue mainQueue] addOperationWithBlock：^ {}];

原因： 这是因为在iOS 8中，警报视图和操作表实际上是视图控制器（UIAlertController）。 因此，如果您正在呈现一个新的视图控制器以响应来自UIAlertView的操作，则会在UIAlertController被解除时显示它。 您需要在主队列上执行此操作而不会干扰导航。