Question

We can add an image to an photo album using

UIImage *img = [UIImage imageNamed:@"ImageName.png"];  

UIImageWriteToSavedPhotosAlbum(img, self, 
          @selector(image:didFinishSavingWithError:contextInfo:), nil);

Is it possible to delete the added image later? If so, how can I give a user the option to delete the added image.

Answer 1

Your question is not very clear, but if you’re using documents directory to save this image, use the following method:

Documents Directory Approach

Save

-(void) saveImage:(UIImage *)image withFileName:(NSString *)imageName ofType:(NSString *)extension inDirectory:(NSString *)directoryPath {
    if ([[extension lowercaseString] isEqualToString:@"png"]) {
        [UIImagePNGRepresentation(image) writeToFile:[directoryPath stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.%@", imageName, @"png"]] options:NSAtomicWrite error:nil];
    } else if ([[extension lowercaseString] isEqualToString:@"jpg"] || [[extension lowercaseString] isEqualToString:@"jpeg"]) {
        [UIImageJPEGRepresentation(image, 1.0) writeToFile:[directoryPath stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.%@", imageName, @"jpg"]] options:NSAtomicWrite error:nil];
    } else {
        ALog(@"Image Save Failed\nExtension: (%@) is not recognized, use (PNG/JPG)", extension);
    }
}

Load

-(UIImage *) loadImage:(NSString *)fileName ofType:(NSString *)extension inDirectory:(NSString *)directoryPath {

    UIImage * result = [UIImage imageWithContentsOfFile:[NSString stringWithFormat:@"%@/%@.%@", directoryPath, fileName, extension]];

    return result;
}

Remove

-(void) removeFile:(NSString *)fileName ofType:(NSString *)extension inDirectory:(NSString *)directory {
    NSFileManager * fileManager = [NSFileManager defaultManager];
    NSError * error = nil;

    if ([[NSFileManager defaultManager] fileExistsAtPath:[directory stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.%@", fileName, extension]]]) {
        BOOL itemRemoved = [fileManager removeItemAtPath:[NSString stringWithFormat:@"%@/%@.%@", directory, fileName, extension] error:&error];
        if (itemRemoved == TRUE) {
            ALog(@"Item \"%@\" Removed", fileName);
        } else {
            ALog(@"Item \"%@\" Removal Failed", fileName);
        }
    } else {
        ALog(@"Item \"%@\" does not exist", fileName);
    }
}

How-To

Save

NSString * path = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
[self saveImage:yourImage withFileName:@"YourImageName" ofType:@"png" inDirectory:path];

Load

NSString * path = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
UIImage * myImage = [self loadImage:@"YourImageName" ofType@"png" inDirectory:path];

Remove

NSString * path = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
[self removeFile:@"YourImageName" ofType:@"png" inDirectory:path];

Note:
The ‘png’ extension is used as default in this case, but you can change it to whatever image extension you’re using.

Photo Albums Approach

Suggestion

Save your files to the documents directory folder using the above methods, read your images within your app. If the user does not like a photo he/she can then delete it from within your app (documents directory). If the user likes the photo, he/she can add it to photo albums or when the application exits you can add code to add the photos to your photo albums.

The documents directory approach is used by many photo applications. The methods above will help you if you use the documents directory approach.