Destroy is the destructor for TIdUDPListenerThread, and is responsible for disposing of the object instance. Destroy frees the internal buffer allocated for reading datagrams from a client connection, and calls the inherited destructor. 

Destroy should not be directly called in an application. Use Free instead. Free checks to ensure that the object reference is not Nil before calling Destroy. 

Note: 

If an exception is emitted from the constructor, the destructor is called to destroy the partially constructed object instance. Destructors should check that allocated resources, such as handles, were actually allocated before trying to release them.