How to call UIImagePickerController Delegate programmatically or forcefully [without user interaction]?

问题

In my app, i have Used UiimagepickerController for taking Video.in bettween my programm received any web service Which belongs to my app, i have to stop Video Capture and save video.

i have Used StopVideoCapture to do above thing ,but it doesn't call delegate - `

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

How to force call above delegate ??.or How to handle interruption Handling inUIImagePickerController`.. any idea?

回答1:

The idea with delegate methods is not that you call those methods - "They call you".

So I would not consider calling the delegate method yourself a good practise. However, if you present the UIImagePickerViewController with a modal dialogue (which I guess is common for such a picker) then you can close it like this outside of your delegate method:

[[yourPicker parentViewController] dismissModalViewControllerAnimated:YES];

Source

Update: You can use the ALAssetsLibrary for accessing the stored data in your iPhone media library. I recently had to do a similar project where I had to list all images on the iPhone. The Github project ELCImagePickerController.git was very useful since it shows how the items in your library can be accessed. So you'll do something like this:

#import <AssetsLibrary/AssetsLibrary.h>

// ....

-(void)fetchPhotoAlbums{

    if(!self.assetsGroups){
        self.assetsGroups = [NSMutableDictionary dictionary];
    }

    ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];      
    NSMutableArray *returnArray = [[NSMutableArray alloc] init];

        @autoreleasepool {
            void (^assetGroupEnumerator)(ALAssetsGroup *, BOOL *) = ^(ALAssetsGroup *group, BOOL *stop){
                if (group == nil){
                   // Completed
                   [self.delegate pictureService:self fetchedAlbums:returnArray]; 
                    return;
                }

                Album *currentAlbum = [self albumForAssetsGroup:group];

                // Store the Group for later retrieving the pictures for the album
                [self.assetsGroups setObject:group forKey:currentAlbum.identifier];
                [returnArray addObject:currentAlbum];
                [self.delegate pictureService:self fetchedAlbums:returnArray];
             };

            void (^assetGroupEnumberatorFailure)(NSError *) = ^(NSError *error) {
                NSLog(@"A problem occured %@", [error description]);                                     
            };  

            [library enumerateGroupsWithTypes:ALAssetsGroupAll
                                   usingBlock:assetGroupEnumerator 
                                 failureBlock:assetGroupEnumberatorFailure];   
        }
}


-(void)fetchPhotosForAlbum:(Album *)album{

    ALAssetsGroup *currentGroup = [self.assetsGroups objectForKey:album.identifier];
    NSMutableArray *photos = [NSMutableArray array];
    [currentGroup enumerateAssetsUsingBlock:^(ALAsset *asset, NSUInteger index, BOOL *stop){         
         if(asset == nil){
             [self.delegate pictureService:self fetchedPictures:photos forAlbum:album];
             return;
         }

         [photos addObject:[self pictureForAsset:asset]];
     }];
}

Additionally I use two mapper methods to convert the AL-classes into my own model classes.

- (Album *)albumForAssetsGroup:(ALAssetsGroup *)assetsGroup{
    Album *album = [[Album alloc] init];
    album.title = [assetsGroup valueForProperty:ALAssetsGroupPropertyName];
    album.identifier = [assetsGroup valueForProperty: ALAssetsGroupPropertyPersistentID];
    album.assetsCount = assetsGroup.numberOfAssets;
    album.thumbnail = [UIImage imageWithCGImage:assetsGroup.posterImage];
    return album;
}

- (Picture *)pictureForAsset:(ALAsset *)asset{
    Picture *picture = [[Picture alloc]init];
    picture.identifier = [((NSArray *)[asset valueForProperty: ALAssetPropertyRepresentations]) objectAtIndex:0];
    picture.thumbnail = [UIImage imageWithCGImage:asset.thumbnail];
    return picture;
}

See the AssetsLibrary Documentation

来源：https://stackoverflow.com/questions/8484758/how-to-call-uiimagepickercontroller-delegate-programmatically-or-forcefully-wit

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iphone

objective-c

ios4

uiimagepickercontroller