iphone - 使用什么来代替已弃用的 UIImagePickerControllerDelegate 方法？

Question

我遵循了一个很棒的教程( http://iphone.zcentric.com/2008/08/28/using-a-uiimagepickercontroller/ )，使用 UIImagePickerController 从 iPhone 上的相册或相机获取图像。问题是，该教程有点过时，并且文档引用了委托(delegate)使用的方法，该方法自 3.0 起已被弃用。问题是，文档未能提供有关使用什么的线索？已弃用的方法是:

– imagePickerController:didFinishPickingImage:editingInfo:

上述方法的使用方法如下:

- (void) imagePickerController:(UIImagePickerController*)picker didFinishPickingImage:(UIImage*)img editingInfo:(NSDictionary*)editInfo
{

    image.image = img;
    [[picker parentViewController] dismissModalViewControllerAnimated:YES];


}

问题:当前使用什么来代替已弃用的方法？

Answer 1

简而言之，以下是如何使用新的图像选择器 API。

首先，您需要一个这样声明的类，因为它将自身设置为图像选择器委托(delegate):

@interface MyClass : UIViewController <UINavigationControllerDelegate, UIImagePickerControllerDelegate> {
UIImagePickerController*    imagePicker;
}
@property(nonatomic,retain) UIImagePickerController* imagePicker;

- (IBAction) takePicture:(id)sender;

@end

调出图像选择器的方法会是这样的。它在此处声明为 IBAction，因此您可以将其直接连接到 Interface Builder 中的控件(如按钮)。它还会进行检查，以便如果您使用 iPhone，它会调出相机界面，但在 iPod Touch 上，它会调出图库选择器:

#import <MobileCoreServices/UTCoreTypes.h>
...
@synthesize imagePicker = _imagePicker;
...

- (void) takePicture:(id)sender
{
        if (!_imagePicker) {
            self.imagePicker = [[UIImagePickerController alloc] init];
            self.imagePicker.delegate = self;
        }

        if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
            self.imagePicker.sourceType = UIImagePickerControllerSourceTypeCamera;
            NSArray* mediaTypes = [UIImagePickerController availableMediaTypesForSourceType:UIImagePickerControllerSourceTypeCamera];
            self.imagePicker.mediaTypes = mediaTypes;
        } else {
            self.imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary; 
            self.imagePicker.allowsImageEditing = YES; 
        }

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

那么你需要这两个方法:

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    [[picker parentViewController] dismissModalViewControllerAnimated:YES]; 

    // MediaType can be kUTTypeImage or kUTTypeMovie. If it's a movie then you
    // can get the URL to the actual file itself. This example only looks for images.
    //   
    NSString* mediaType = [info objectForKey:UIImagePickerControllerMediaType];
    // NSString* videoUrl = [info objectForKey:UIImagePickerControllerMediaURL];

    // Try getting the edited image first. If it doesn't exist then you get the
    // original image.
    //
    if (CFStringCompare((CFStringRef) mediaType, kUTTypeImage, 0) == kCFCompareEqualTo) {       
        UIImage* picture = [info objectForKey:UIImagePickerControllerEditedImage];
        if (!picture)
            picture = [info objectForKey:UIImagePickerControllerOriginalImage];     

            // **You can now do something with the picture.
    }
    self.imagePicker = nil;
}

- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker 
{ 
    [[picker parentViewController] dismissModalViewControllerAnimated:YES]; 
    self.imagePicker = nil;
}