新手求教camera程序解读

求教各位高手,这段代码是做什么用的,拜托大概加点注释,
比如是做什么用的,用什么类什么方法,选到的文件保存在哪里  这样的,小弟拜谢了!!
#import "CameraViewController.h"@implementation CameraViewController
@synthesize imageView;
@synthesize takePictureButton;
@synthesize selectFromCameraRollButton;- (void)viewDidLoad {
    if (![UIImagePickerController isSourceTypeAvailable:
          UIImagePickerControllerSourceTypeCamera]) {
        takePictureButton.hidden = YES;
        selectFromCameraRollButton.hidden = YES;
    }
}
- (void)viewDidUnload {
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
    self.imageView = nil;
    self.takePictureButton = nil;
    self.selectFromCameraRollButton = nil;
    [super viewDidUnload];
}
- (void)dealloc {
    [imageView release];
    [takePictureButton release];
    [selectFromCameraRollButton release];
    [super dealloc];
}
#pragma  -
- (IBAction)getCameraPicture:(id)sender {
    UIImagePickerController *picker =
    [[UIImagePickerController alloc] init];
    picker.delegate = self;
    picker.allowsImageEditing = YES;
    picker.sourceType = (sender == takePictureButton) ? 
    UIImagePickerControllerSourceTypeCamera :
    UIImagePickerControllerSourceTypeSavedPhotosAlbum;
    [self presentModalViewController:picker animated:YES];
    [picker release];
    
}
- (IBAction)selectExistingPicture {
    if ([UIImagePickerController isSourceTypeAvailable:
         UIImagePickerControllerSourceTypePhotoLibrary]) {
        UIImagePickerController *picker =
        [[UIImagePickerController alloc] init];
        picker.delegate = self;
        picker.allowsImageEditing = YES;
        picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
        [self presentModalViewController:picker animated:YES];
        [picker release];
    }
    else {
        UIAlertView *alert = [[UIAlertView alloc] 
                              initWithTitle:@"Error accessing photo library" 
                              message:@"Device does not support a photo library" 
                              delegate:nil 
                              cancelButtonTitle:@"Drat!" 
                              otherButtonTitles:nil];
        [alert show];
        [alert release];
    }
}
#pragma   -
- (void)imagePickerController:(UIImagePickerController *)picker 
        didFinishPickingImage:(UIImage *)image
                  editingInfo:(NSDictionary *)editingInfo {
    imageView.image = image;
    [picker dismissModalViewControllerAnimated:YES];
    
}
- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker {
    
    [picker dismissModalViewControllerAnimated:YES];
}
@end