如何避免将从相机胶卷中挑选的图像保存到相机胶卷？ [iOS]

Question

我可以轻松地将用相机拍摄的图像保存到相机胶卷。 但如果这是从相机胶卷中选择的，我不想保存图像，因为它会创建一个副本。

如何执行以下操作并有选择地保存到相机胶卷？

编辑 1： 正如 rmaddy 所说，我可以： 仅当 picker.sourceType 等于 UIImagePickerControllerSourceTypeCamera 时才保存到相机胶卷。

但如果我这样做，我将无法获取所选图像的信息，主要是文件名。

-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
NSString *mediaType = [info objectForKey:UIImagePickerControllerMediaType];

if ([mediaType isEqualToString:(NSString *)kUTTypeImage]) {
    UIImage *image = [info objectForKey:UIImagePickerControllerOriginalImage];

    [self.myImageView setImage: image];
    [self.myImageView setContentMode:UIViewContentModeScaleAspectFit];
    ALAssetsLibrary *al=[[ALAssetsLibrary alloc] init];

    // ------> Saving to Camera Roll <------------

    [al writeImageToSavedPhotosAlbum:[image CGImage] metadata:nil completionBlock:^(NSURL *assetURL,NSError *error) { 

            ALAssetsLibraryAssetForURLResultBlock resultblock = ^(ALAsset *myAsset) {
                ALAssetRepresentation *rep = [myAsset defaultRepresentation];
                NSString *fileName = [rep filename];
                ImageInfo *imgInfo = [[ImageInfo alloc] initWithEventId:0 name:fileName image:UIImageJPEGRepresentation(image, 1.0)];
                imgInfo.isDirty = YES;
                [self.imagesArray addObject:imgInfo];
                [self dismissViewControllerAnimated:YES completion:nil];
                NSLog(@"Image from Camera %@ added to imageArray",fileName);
            };

            ALAssetsLibrary *assetsLibrary = [[ALAssetsLibrary alloc]init];
            [assetsLibrary assetForURL:assetURL
                           resultBlock:resultblock
                          failureBlock:nil];

     }];
}
else if ([mediaType isEqualToString:(NSString *)kUTTypeMovie])
{
    // Code here to support video if enabled
}

编辑2：

用这个 MOD 解决了： （知道有一点代码重复，以后会努力改进的）

if (newMedia){
        ALAssetsLibrary *al=[[ALAssetsLibrary alloc] init];
        [al writeImageToSavedPhotosAlbum:[image CGImage] metadata:nil completionBlock:^(NSURL *assetURL,NSError *error)
        {                
            ALAssetsLibraryAssetForURLResultBlock resultblock = ^(ALAsset *myAsset)
            {
                ALAssetRepresentation *rep = [myAsset defaultRepresentation];
                //NSString *fileName = [rep filename];
                NSString *imgUrl = [[rep url] absoluteString];
                ImageInfo *imgInfo = [[ImageInfo alloc] initWithEventId:0 imgUrl:imgUrl image:UIImageJPEGRepresentation(image, 1.0)];
                imgInfo.isDirty = YES;
                [self.imagesArray addObject:imgInfo];
                [self dismissViewControllerAnimated:YES completion:nil];
                NSLog(@"Image from Camera %@ added to imageArray",imgUrl);
            };

            ALAssetsLibrary *assetsLibrary = [[ALAssetsLibrary alloc]init];
            [assetsLibrary assetForURL:assetURL
                           resultBlock:resultblock
                          failureBlock:nil];
        }];
} else {
        NSString* imgUrl = UIImagePickerControllerReferenceURL;
        ImageInfo *imgInfo = [[ImageInfo alloc] initWithEventId:0 imgUrl:imgUrl image:UIImageJPEGRepresentation(image, 1.0)];
        imgInfo.isDirty = YES;
        [self.imagesArray addObject:imgInfo];
        NSLog(@"Image from Camera Roll %@ added to imageArray",imgUrl);
        [self dismissViewControllerAnimated:YES completion:nil];
}

Answer 1

仅当picker.sourceType 等于UIImagePickerControllerSourceTypeCamera 时才保存到相机胶卷。