Returns a status indicating whether the value for a given key is immediately available without blocking the calling thread.
- iOS 4.0+
- macOS 10.7+
- Mac Catalyst 13.0+
- tvOS 9.0+
- watchOS 6.0+
The current loading status of the value for
AVKey for the defined keys.
You use this method to determine the availability of the value for a key. This method does not cause an asset to load the value of a key that’s not yet available. To request values for keys that may not already be loaded without blocking, use
load and wait for invocation of the completion handler to be informed of availability.