# detectValuesForPatterns:inItemSet:completionHandler: Determines whether pasteboard items match the specified patterns, reading the contents if it finds a match. ``` - (void) detectValuesForPatterns:(NSSet *) patterns inItemSet:(NSIndexSet *) itemSet completionHandler:(void (^)(NSArray *> *, NSError *)) completionHandler; ``` ## Parameters `patterns` The patterns to detect on the pasteboard. `itemSet` An index set with each integer value identifying a pasteboard item positionally in the pasteboard. Pass in nil to request all pasteboard items. `completionHandler` A block that the system invokes after detecting patterns on the pasteboard. The block receives a `Result` instance that contains either an array of dictionaries with the patterns and the associated values found on the pasteboard or an error if detection failed. If `Result` contains an array, the index of each element in the array corresponds to the pasteboard item index specified in `itemSet`. ## Discussion > Important: > Calling this method notifies the user that the app has read the contents of the pasteboard. For details about the types returned for each pattern, see [`UIPasteboard.DetectionPattern`](/documentation/UIKit/UIPasteboard/DetectionPattern). --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)