I have a textbox bound to a custom object property that accepts only
positive percentages as values.  I use a regular expression in the
'Validating' event to check the entered data.  The regex is written such
that the user can enter 0.25 or 25% and the result will be the same.  It
does not allow negative values.

There is also a 'Parse' and 'Format' handler associated with the
databinding.  The Parse converts the entered data into a number and the
format converts it back to a string with the '%' appended.

If the user enters an invalid value (i.e. -5%), the Validating event
seems to work correctly, but the Parse and Format events still trigger
despite setting e.cancel in the validating event.

Ideally, the Parse and Format events would not fire unless the
validating succeeds.

Any ideas on how to handle this?

Thanks.