# CFUserNotificationReceiveResponse(_:_:_:) Waits for the user to respond to a notification or for the notification to time out. ``` func CFUserNotificationReceiveResponse(_ userNotification: CFUserNotification!, _ timeout: CFTimeInterval, _ responseFlags: UnsafeMutablePointer!) -> Int32 ``` ## Parameters `userNotification` The user notification to use. `timeout` The amount of time to wait for the user to respond to `userNotification` or for the notification to time out. If neither happens before `timeout` passes, this function returns a non-`0` value. If `timeout` is `0`, the function blocks until the user notification is dismissed. `responseFlags` On return, contains flags identifying how the notification was dismissed, the state of any checkboxes, and the selected element of the pop-up menu. Bits 0-1 of the value hold an identifier for the button pressed by the user (see [Response Codes](/documentation/CoreFoundation/1534504-response-codes)). Extract the identifier by performing a bitwise-AND operation with `0x3`. Bits 8-15 of `responseFlags` hold the state of up to 8 checkboxes or radio buttons, if present. Extract the flags by performing bitwise-AND operations with the return value of [`CFUserNotificationCheckBoxChecked(_:)`](/documentation/CoreFoundation/CFUserNotificationCheckBoxChecked(_:)). Bits 24-31 hold the index number of the element selected in a pop-up menu, if present. Extract the index by performing a 24-bit right shift: `responseFlags >> 24`. ## Return Value `0` if the call successfully received a response; a non-`0` value otherwise. ## Discussion Use this function to poll a user notification for a user response. You can call it any number of times on the same user notification. To avoid polling and blocking your thread’s execution, you can create a run loop source for the user notification with [`CFUserNotificationCreateRunLoopSource(_:_:_:_:)`](/documentation/CoreFoundation/CFUserNotificationCreateRunLoopSource(_:_:_:_:)). You will then receive a callback when the dialog is dismissed. --- 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)