Using Xcode, create a View-based Application project and name it PhotoLibrary.

Double-click the PhotoLibraryViewController.xib file to edit it in Interface Builder.

Populate the View window with the following views (see Figure 16-5):

In the Attributes Inspector window for the ImageView view, set the Mode to Aspect Fit.

In the PhotoLibraryViewController.h file, insert the following statements that appear in bold:

##import <UIKit/UIKit.h>

@interface PhotoLibraryViewController : UIViewController
    <UINavigationControllerDelegate, UIImagePickerControllerDelegate> {

    IBOutlet UIImageView *imageView;
    UIImagePickerController *imagePicker;
}

@property (nonatomic, retain) UIImageView *imageView;

-(IBAction) btnClicked: (id) sender;

@end

Back in Interface Builder, Control-click and drag the File's Owner item to the ImageView view and select imageView.

Control-click and drag the Button view to the File's Owner item select btnClicked:.

In the PhotoLibraryViewController.m file, insert the following statements that appear in bold:

#import "PhotoLibraryViewController.h"

@implementation PhotoLibraryViewController

@synthesize imageView;

- (void)viewDidLoad {
    imagePicker = [[UIImagePickerController alloc] init];

[super viewDidLoad];
}

- (IBAction) btnClicked: (id) sender{
    imagePicker.delegate = self;
    imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;

    //---show the Image Picker---
    [self presentModalViewController:imagePicker animated:YES];
}

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

    UIImage *image;
    NSURL *mediaUrl;

    mediaUrl = (NSURL *)[info valueForKey:UIImagePickerControllerMediaURL];

    if (mediaUrl == nil)
    {
        image = (UIImage *) [info valueForKey:UIImagePickerControllerEditedImage];
        if (image == nil)
        {
            //---original image selected---
            image = (UIImage *)
                [info valueForKey:UIImagePickerControllerOriginalImage];

            //---display the image---
            imageView.image = image;
        }
        else //---edited image picked---
        {
            //---get the cropping rectangle applied to the image---
            CGRect rect =
                [[info valueForKey:UIImagePickerControllerCropRect] CGRectValue ];

            //---display the image---
            imageView.image = image;
        }
    }
    else
    {
        //---video picked---
        //...
    }

    //---hide the Image Picker---
    [picker dismissModalViewControllerAnimated:YES];
}

- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker
{

//---user did not select image/video; hide the Image Picker---
    [picker dismissModalViewControllerAnimated:YES];
}

- (void)dealloc {
    [imageView release];
    [imagePicker release];
    [super dealloc];
}

Press Command-R to test the application on the iPhone Simulator.

When the application is loaded, tap the Load Photo Library button, and the Photo Albums on the iPhone Simulator appears (see Figure 16-6). Select a picture; the selected picture is then displayed on the ImageView view.

Figure 16.6. Figure 16-6

Using the same project created in the previous section, edit the PhotoLibraryViewController.m file and change the source type of the Image Picker to camera (see code highlighted in bold):

-(IBAction) btnClicked: (id) sender{
    imagePicker.delegate = self;

    //---comment this out---
    //imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;

    //---invoke the camera---
    imagePicker.sourceType = UIImagePickerControllerSourceTypeCamera;

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

In PhotoLibraryViewController.h file, declare the following two methods highlighted in bold so that you can save the image captured by the camera to the application's Documents folder (on the device):

#import <UIKit/UIKit.h>

@interface PhotoLibraryViewController : UIViewController
    <UINavigationControllerDelegate, UIImagePickerControllerDelegate> {

    IBOutlet UIImageView *imageView;
    UIImagePickerController *imagePicker;
}

@property (nonatomic, retain) UIImageView *imageView;

-(IBAction) btnClicked: (id) sender;

- (NSString *) filePath: (NSString *) fileName;
- (void) saveImage;

@end

In the PhotoLibraryViewController.m file, define the two methods that you have declared in the previous step:

- (NSString *) filePath: (NSString *) fileName {
    NSArray *paths = NSSearchPathForDirectoriesInDomains(
                     NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDir = [paths objectAtIndex:0];
    return [documentsDir stringByAppendingPathComponent:fileName];
}

- (void) saveImage{
    //---get the date from the ImageView---
    NSData *imageData =
        [NSData dataWithData:UIImagePNGRepresentation(imageView.image)];

//---write the date to file---
    [imageData writeToFile:[self filePath:@"MyPicture.png"] atomically:YES];
}

Right-click the Frameworks group in Xcode and choose Add

In the PhotoLibraryViewController.h file, import the following header file:

#import <UIKit/UIKit.h>
#import <MediaPlayer/MediaPlayer.h>

Insert the following statements that appear in bold:

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

    UIImage *image;
    NSURL *mediaUrl;

    mediaUrl = (NSURL *)[info valueForKey:UIImagePickerControllerMediaURL];
    if (mediaUrl == nil)
    {
        image = (UIImage *) [info valueForKey:UIImagePickerControllerEditedImage];
        if (image == nil)
        {
            //---original image selected---
            image = (UIImage *)
                [info valueForKey:UIImagePickerControllerOriginalImage];

            //---display the image---
            imageView.image = image;

            //---save the image captured---
            [self saveImage];
        }
        else
        {
            //---edited image picked---
            //---get the cropping rectangle applied to the image---
            CGRect rect =
                [[info valueForKey:UIImagePickerControllerCropRect] CGRectValue ];

            //---display the image---
            imageView.image = image;

            //---save the image captured---
            [self saveImage];
        }
    }
    else

{
        //---video picked---
        MPMoviePlayerController *player = [[MPMoviePlayerController alloc]
                                              initWithContentURL:mediaUrl];
        [player play];
    }

    //---hide the Image Picker---
    [picker dismissModalViewControllerAnimated:YES];
}

Press Command-R to test the application on a real iPhone.

Tap the Load Photo Library button, and you are now able to use your iPhone's camera to take photos and videos. If you use it to take a picture, the picture you take is saved onto the Document folder of your application. If you take a video, the video can be played back using the media player on your device.