typedef TAdapterFieldValidateValueEvent TAdapterFieldValidateValueEvent;
TAdapterFieldValidateValueEvent is the type for event handlers that validate a value for an adapter field.
TAdapterFieldValidateValueEvent is the type for event handlers that let you check whether a value is valid for a given adapter field. The event handler raises an exception if the value is not valid.
Sender is the adapter field component whose value needs to be validated.
AValue is an interface for obtaining the value of the adapter field.
Handled returns true if the event handler has checked the value, false if the event handler did not validate the value. Note that if the event handler checks the value and finds it invalid, it does not set Handled to false: rather, it raises an exception.