IEnumConnections interface

Enumerates the current connections for a connectable object.

When to implement

To support connectable objects, you need to implement four related interfaces:

• IConnectionPointContainer
• IEnumConnectionPoints
• IConnectionPoint
• IEnumConnections

The IConnectionPointContainer interface indicates the existence of the outgoing interfaces. It provides access to an enumerator sub-object with the IEnumConnectionPoints interface. It also provides a connection point sub-object with the IConnectionPoint interface. The IConnectionPoint interface provides access to an enumerator sub-object with the IEnumConnections interface.

Each connection point is a separate sub-object to avoid circular reference counting problems.

Any individual connection point can support enumeration of its currently known connections through IConnectionPoint::EnumConnections. The enumerator created by this method implements the interface IEnumConnections, which deals with the type CONNECTDATA. Each CONNECTDATA structure contains the IUnknown of a connected sink and the dwConnection that was returned by IConnectionPoint::Advise when that sink was connected. When enumerating connections through IEnumConnections, the enumerator is responsible for calling AddRef through the pointer in each enumerated structure, and the caller is responsible for calling Release when those pointers are no longer needed.

When to use

Use the IEnumConnections interface to enumerate the current connections.

Members

The IEnumConnections interface inherits from the IUnknown interface. IEnumConnections also has these types of members:

• Methods

Methods

The IEnumConnections interface has these methods.

Remarks

Connectable objects support the following features:

• Outgoing interfaces, such as event sets
• The ability to enumerate the IIDs of the outgoing interfaces
• The ability to connect and disconnect sinks to the object for those outgoing IIDs
• The ability to enumerate the connections that exist to a particular outgoing interface

Requirements

See also

IConnectionPoint

IConnectionPointContainer

IEnumConnectionPoints