DOFSystemquery Method (DOFObjectID, DOFInterfaceID)OpenDOF Object Access Library
Used by a Requestor to query for the set of currently available objects, which provide interfaces that match the specified query.

Namespace: org.opendof.core.oal
Assembly: dof-oal (in dof-oal.dll) Version: 7.0.1.2
Syntax
C#
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public IList<DOFObjectID> query(
	DOFObjectID oid,
	DOFInterfaceID iid
)

Parameters

oid
Type: org.opendof.core.oalDOFObjectID
Object ID to match. May be null.
iid
Type: org.opendof.core.oalDOFInterfaceID
Interface ID to match. May be null.

Return Value

Type: IListDOFObjectID
The set of DOFObjectIDs for the currently available objects providing the specified query.
Remarks
Used by a Requestor to query for the set of currently available objects, which provide interfaces that match the specified query.

NOTE: An application must first express interest by calling beginInterest(DOFObjectID, DOFInterestLevel) . Interest goes out on the network and looks for matching providers. query, on the other hand, searches through the local set of known providers (those already found through interest).

  • If oid and iid are null then the query matches all provides compatible with the system.
  • If only the oid is null then the query matches any object providing the specified interface
  • If only the iid is null then the query matches the given object providing any interface.
  • If both the oid and iid are specified the query matches only the specified object providing the specified interface.
See Also

Reference

DOFSystem Class
query Overload
org.opendof.core.oal Namespace
beginQuery(DOFQuery, QueryOperationListener)