ios4 - 正确发布UIImagePickerController

Question

我对此有点困惑，因为我见过太多不同的变体，并且不确定哪一个是正确的方法。目前我有:

- (IBAction)pickImageFromLibrary:(id)sender
{
    UIImagePickerController *picker = [[UIImagePickerController alloc] init];

    picker.delegate = self;
    picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;

    [self presentModalViewController:picker animated:YES];

    //  [picker release];
}

- (void)imagePickerController:(UIImagePickerController *)picker
didFinishPickingMediaWithInfo:(NSDictionary *)info
{   
    UIImage *image = [info objectForKey:@"UIImagePickerControllerOriginalImage"];

    UIImageView *imageView = [[UIImageView alloc]initWithFrame:CGRectMake(0.0f, 10.0f, 320.0f, 264.0f)];

    self.studyView = imageView;

    [imageView release];

    [self.tableView setTableHeaderView:studyView];

    self.fitImage = [ImageHelper image:image fitInView:studyView];

    if (picker.sourceType == UIImagePickerControllerSourceTypeCamera)
    {
        UIImageWriteToSavedPhotosAlbum(image, self, @selector(image:didFinishSavingWithError:contextInfo:), nil);
    }

    studyView.image = self.fitImage;

    [self dismissModalViewControllerAnimated:YES];

    [picker release];
 }

我在第一个方法中分配了UIImagePickerController，但是当我关闭它时仅在第二个方法中释放它不是合乎逻辑的吗？

Answer 1

不，因为它在通过 presentModelViewController 以模态方式呈现时被保留。这是在呈现新 View Controller 时会发现的常见模式，无论是否是模态视图 Controller 、自定义 View Controller 。这很好:

- (IBAction)pickImageFromLibrary:(id)sender
{
    UIImagePickerController *picker = [[UIImagePickerController alloc] init];

    picker.delegate = self;
    picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;

    [self presentModalViewController:picker animated:YES];

    [picker release];
}