MonitorStart (OraAQ) Method

Applies To

Description

Starts a monitor thread for dequeuing the messages specified.

Usage

Q.MonitorStart NotificationHandler, CallbackCtx, MsgFilterVal,MsgFilter

Arguments

The arguments for the method are:

Arguments	Description
[`in`] `NotificationHandler`	An `IDispatch` interface containing the callback method (`NotifyMe`) which should be notified of new messages.
[`in`] `CallbackCtx`	Context-specific information that the application wants to pass to the `NotifyMe` method. This is passed into the `NotifyMe` method whenever a new message satisfying the user criteria is dequeued.
[`in`] [optional] `MsgFilterVal`	A byte array containing a value for the message filter. Ignored if `MsgFilter` is `ORAAQ_ANY`.
[`in`] [optional] `MsgFilter`	An `Integer` constant specifying the selection criteria for messages. Possible values for `MsgFilter` are: `ORAAQ_ANY` = `0` - Invokes the callback for any message that arrives on the queue. This is the default value. `ORAAQ_CONSUMER` = `1` - Invokes the callback when the message intended for the consumer given in the `MsgFilterValue` is dequeued. `ORAAQ_MSGID` = `2` - Invokes the callback when message with the identifier specified in `MsgFilterVal` is dequeued.

Remarks

NotifyMe is the callback method of the notification object. The syntax of the method is:

Public Sub NotifyMe (ByVal Ctx As Variant, ByVal Msgid As Variant)

Variants	Description
`[in]` `Ctx`	Value passed into the `MonitorStart` method by the application. Context-sensitive information that the application wants to pass in when messages are dequeued.
`[in]` `Msgid`	The message ID of the newly dequeued message. The `Msgid` variant is null when there is an error while monitoring.

By default, the message is passed into NotifyMe in Remove mode. The default dequeue options can be overridden by setting the properties of this instance (OraAQ).

The MonitorStart method returns ORAAQ_SUCCESS or ORAAQ_FAIL.