Public Function SetState( _
   ByVal Active As Nullable(Of Boolean), _
   ByVal BufferTime As Nullable(Of Integer), _
   ByVal MaxSize As Nullable(Of Integer), _
   ByVal ClientSubscription As Integer, _
   ByRef RevisedBufferTime As Integer, _
   ByRef RevisedMaxSize As Integer _
) As Integer

public int SetState( 
   Nullable<bool> Active,
   Nullable<int> BufferTime,
   Nullable<int> MaxSize,
   int ClientSubscription,
   out int RevisedBufferTime,
   out int RevisedMaxSize
)

Parameters

Active

TRUE (non-zero) to activate the subscription.
FALSE (0) to deactivate the subscription. If the client deactivates the subscription, then the server will no longer send event notifications to the client based on that subscription, and has no responsibility to buffer or maintain the event notifications. Thus event notifications may be lost. Even if the subscription is inactive, the Refresh method will still function. In effect, this allows a client to obtain current condition states from time to time (by invoking Refresh) without the need to process event notifications in “real time”.

BufferTime

New buffer time requested for the subscription by the client. If the revised buffer time does not equal the requested buffer time, then the server must return OPC_S_INVALIDBUFFERTIME, unless pdwMaxSize is also invalid in which case the server must return OPC_S_INVALIDMAXSIZE. See the discussion in EventSubscriptionMgt.Create.

MaxSize

New maximum number of event notifications to send with a single IOPCEventSink::OnEvent callback. If the requested MaxSize does not equal the revised MaxSize then the Server must return OPC_S_INVALIDMAXSIZE. See the discussion in EventSubscriptionMgt.Create.

ClientSubscription

Client supplied handle for the subscription. This handle is returned in the data stream provided to the client’s OnAEeventHandler. Note that this is not a pointer, so you must pass the existing handle even if you do not want to change it.

RevisedBufferTime

The buffer time that the server is actually providing, which may differ from dwBufferTime.

RevisedMaxSize

The maximum number of events that the server will actually be sending in a single OnAEeventHandler callback, which may differ from dwMaxSize.

Return Value

Target Platforms: Windows 7/8/10, Windows Server 2003/2008/2012/2016, .NET 4.x

See Also