Consultor Eletrônico

Status: Verified

GOAL:

Handling of Asynchronous COM Events and -filterocxevents

GOAL:

There are certain OCX events (like timer events) that are essentially asynchronous.  You can prevent these asynchronous events from being processed at certain times by specifying -filterocxevents.

FACT(s) (Environment):

Progress 9.1C
Progress 9.1D

FIX:

In Progress 9.1C, there is a new startup parameter, -filterocxevents, that handles asynchronous COM events differently than in previous versions.  An "asynchronous" COM event is one that is sent by an ActiveX control or Automation object because of an external event, rather than in response to user input.  One example of this is the Tick event from the PSTimer.  Another is an event signaling the receipt of a message from an external source, such as a control that implements a mail notification system.

By default, asynchronous COM events are handled when any of the following conditions occur:

1) While an application is waiting for user input, such as during a WAIT-FOR or UPDATE statement.

2) While an alert box from a MESSAGE statement is on the screen.

3) During trigger processing, if the MultitaskingInterval parameter is set to a number greater than 0.

Handling COM events during the second and third conditions might cause random problems in your application, depending on what 4GL code is executed in the event trigger.  To prevent asynchronous COM events from being handled during the second and third conditions, use the -filterocxevents startup parameter.