OnAfterBind is a TNotifyEvent property that represents the event handler signalled after allocating and binding the socket handle for the socket-based IOHandler. 

OnAfterBind is signalled during processing in the Open method after the Binding for the socket-based IOHandler has been allocated, initalized, and connected. 

Applications must assign a procedure to the event handler to allow responding to the TNotifyEvent event notification. 

Use the Owner property to access properties and methods of the TIdTCPClientCustom or descendant that owns the socket-based IOHandler.