objective-c - 访问 cameraroll 并在 iPad 中选择图像后无法在 UIimageView 控制器上加载图像

Question

我今天遇到了一个有点棘手的情况。我按照http://www.techotopia.com/index.php/An_Example_iOS_4_iPad_Camera_and_UIImagePickerController_Application_%28Xcode_4%29下的教程进行操作

如果编码是在 ViewController.h 和 ViewController.m 下完成的，本教程帮助我访问相机和相机胶卷。

如果我尝试创建一个新的 UIViewController 并将其命名为“相机”并尝试将相同的代码放入其中并尝试通过 ViewController.m 中的按钮操作进行访问，cameraviewcontroller 会加载视图和相机，相机胶卷也会起作用，但是当我选择视图重定向的特定图像。

@implementation ViewController
- (IBAction)button:(id)sender {

    UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard" bundle:nil];
    UIViewController *vc = [storyboard instantiateViewControllerWithIdentifier:@"Camera"];
    [vc setModalPresentationStyle:UIModalPresentationFullScreen];
    [self presentModalViewController:vc animated:YES];


}

//camera.h//

#import <UIKit/UIKit.h>
#import <MobileCoreServices/MobileCoreServices.h>
@interface Camera :UIViewController<UIImagePickerControllerDelegate,
UINavigationControllerDelegate, UIPopoverControllerDelegate>

{
    UIToolbar *toolbar;
    UIPopoverController *popoverController;
    UIImageView *imageView;
    BOOL newMedia;
}

@property (nonatomic, retain) IBOutlet UIImageView *imageView;
@property (nonatomic, retain) UIPopoverController *popoverController;
@property (nonatomic, retain) IBOutlet UIToolbar *toolbar;

- (IBAction)useCamera: (id)sender;
- (IBAction)useCameraRoll: (id)sender;

@end

//camera.m//

#import "Camera.h"

@interface Camera ()

@end

@implementation Camera
@synthesize imageView, popoverController, toolbar;

- (IBAction) useCamera: (id)sender
{
    if ([UIImagePickerController isSourceTypeAvailable:
         UIImagePickerControllerSourceTypeCamera])
    {
        UIImagePickerController *imagePicker =
        [[UIImagePickerController alloc] init];
        imagePicker.delegate = self;
        imagePicker.sourceType =
        UIImagePickerControllerSourceTypeCamera;
        imagePicker.mediaTypes = [NSArray arrayWithObjects:
                                  (NSString *) kUTTypeImage,
                                  nil];
        imagePicker.allowsEditing = NO;
        [self presentModalViewController:imagePicker
                                animated:YES];
        newMedia = YES;
    }
}

- (IBAction) useCameraRoll: (id)sender
{
    if ([self.popoverController isPopoverVisible]) {
        [self.popoverController dismissPopoverAnimated:YES];
    } else {
        if ([UIImagePickerController isSourceTypeAvailable:
             UIImagePickerControllerSourceTypeSavedPhotosAlbum])
        {
            UIImagePickerController *imagePicker =
            [[UIImagePickerController alloc] init];
            imagePicker.delegate = self;
            imagePicker.sourceType =
            UIImagePickerControllerSourceTypePhotoLibrary;
            imagePicker.mediaTypes = [NSArray arrayWithObjects:
                                      (NSString *) kUTTypeImage,
                                      nil];
            imagePicker.allowsEditing = NO;

            self.popoverController = [[UIPopoverController alloc]
                                      initWithContentViewController:imagePicker];

            popoverController.delegate = self;

            [self.popoverController 
             presentPopoverFromBarButtonItem:sender
             permittedArrowDirections:UIPopoverArrowDirectionAny
             animated:YES];
            newMedia = NO;
        }
    }
}

- (void)viewDidLoad
{
    UIBarButtonItem *cameraButton = [[UIBarButtonItem alloc] 
                                     initWithTitle:@"Camera"
                                     style:UIBarButtonItemStyleBordered
                                     target:self
                                     action:@selector(useCamera:)];
    UIBarButtonItem *cameraRollButton = [[UIBarButtonItem alloc] 
                                         initWithTitle:@"Camera Roll"
                                         style:UIBarButtonItemStyleBordered
                                         target:self
                                         action:@selector(useCameraRoll:)];
    NSArray *items = [NSArray arrayWithObjects: cameraButton,
                      cameraRollButton, nil];
    [toolbar setItems:items animated:NO];
    [super viewDidLoad];
}

- (void)viewDidUnload
{
    [super viewDidUnload];
    // Release any retained subviews of the main view.
}

-(void)imagePickerController:(UIImagePickerController *)picker
didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    [self.popoverController dismissPopoverAnimated:true];
    NSString *mediaType = [info
                           objectForKey:UIImagePickerControllerMediaType];
    [self dismissModalViewControllerAnimated:YES];
    if ([mediaType isEqualToString:(NSString *)kUTTypeImage]) {
        UIImage *image = [info
                          objectForKey:UIImagePickerControllerOriginalImage];

        imageView.image = image;
        if (newMedia)
            UIImageWriteToSavedPhotosAlbum(image,
                                           self,  
                                           @selector(image:finishedSavingWithError:contextInfo:),
                                           nil);
    }
    else if ([mediaType isEqualToString:(NSString *)kUTTypeMovie])
    {
        // Code here to support video if enabled
    }
}

-(void)image:(UIImage *)image
finishedSavingWithError:(NSError *)error
 contextInfo:(void *)contextInfo
{
    if (error) {
        UIAlertView *alert = [[UIAlertView alloc]
                              initWithTitle: @"Save failed"
                              message: @"Failed to save image"\
                              delegate: nil
                              cancelButtonTitle:@"OK"
                              otherButtonTitles:nil];
        [alert show];
    }
}

-(void)imagePickerControllerDidCancel:(UIImagePickerController *)picker
{
    [self dismissModalViewControllerAnimated:YES];
}

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    return YES;
}

@end

我已经用谷歌搜索找到解决方案，但是我没有解决方案，请帮助我克服这个问题。

提前致谢。