ThreadedEvent is a Boolean property that indicates if the UDP server is using a seperate thread to perform reads for the UDP connection, or if reads must be synchronised to the main thread of execution for the Server when calling the OnUDPRead event handler. 

ThreadedEvent is used during execution of the TIdUDPListenerThread for the server when an incoming datagram is detected or an exception is encountered for one the server Bindings. 

The TIdUDPListenerThread.UDPRead method is used to handle read notifications, and uses Synchronize to wrap calls to the method when ThreadedEvent is False. 

Datagram packets are extracted from the internal Indy buffer using the OnUDPRead event handler for the active socket binding. Datagram packets are extracted from the internal Indy buffer using the OnUDPRead event handler for the active socket binding. 

The TIdUDPListenerThread.UDPException method is used to handle exception notifications, and uses Synchronize to wrap calls to the method when ThreadedEvent is False. 

The default value for ThreadedEvent is False.

TIdUDPListenerThread.UDPRead 

TIdUDPListenerThread.UDPException 

Bindings 

OnUDPRead 

OnUDPException