NSMetadataQuery.DidStartGatheringMessage
A message a metadata query sends when it starts the initial result-gathering phase of the query.
Declaration
struct DidStartGatheringMessageOverview
Observe this message with the identifier didStartGathering, or specify its type directly to the addObserver(of:for:using:) method. The Subject of this message type is NSMetadataQuery.
This message interoperates with the notification NSMetadataQueryDidStartGathering. The system notifies observers of the message when the NotificationCenter posts the notification. Similarly, the system notifies observers of the notification when it posts the message.