Getting All Screenshots with Photos.framework

PhotosScreenshot.m

    NSMutableArray *mArray = [NSMutableArray array];
    
    // fetch all image assets
    PHFetchOptions *fetchOptions = [[PHFetchOptions alloc] init];
    fetchOptions.predicate = [NSPredicate predicateWithFormat:@"mediaType == %d", PHAssetMediaTypeImage];
    PHFetchResult *result = [PHAsset fetchAssetsWithOptions:fetchOptions];
    [result enumerateObjectsUsingBlock:^(PHAsset * __nonnull asset, NSUInteger idx, BOOL * __nonnull stop) {
        // filter with subtype for screenshot
        if (asset.mediaSubtypes & PHAssetMediaSubtypePhotoScreenshot) {
            [mArray addObject:asset];
        }
    }];
    
    // ex. retrieve image data
    PHAsset *asset = result.firstObject;
    PHImageRequestOptions *options = [[PHImageRequestOptions alloc] init];
    options.synchronous = YES;
    [[PHImageManager defaultManager] requestImageDataForAsset:asset options:options resultHandler:^(NSData * __nullable imageData, NSString * __nullable dataUTI, UIImageOrientation orientation, NSDictionary * __nullable info) {
        UIImage *image = [UIImage imageWithData:imageData];
        NSLog(@"%@", image);
        // stop at this point with breakpoint, you can see quicklook
    }];