How to use UIImagePickerController in iPad?

Hi i am working on a universal application (iPhone/iPad). one feature is that i have to select a photo from album and show it on UIImageView.

Now problem is that it is working good on iPhone but when i try to open photo album it crashes. my code in action sheet delegate is this:

- (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];
            }
        }


    }


}

can any body help me out? i have checked on stackOverflow and also googled it but in vain.

UIImagePickerController must be presented with UIPopoverController on iPad.

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];
}

EDIT: Add a strong property for the UIPopoverController:

@property (nonatomic, strong) UIPopoverController *popOver;

The popover should be dismissed in the delegate methods:

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

-(void)imagePickerControllerDidCancel:(UIImagePickerController *)picker 

Here i show you the SWIFT way:

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)
    }
}