Implement this interface as part of support for connectable objects. To create a connectable object, you need to implement objects that provide four related interfaces:

• IConnectionPointContainer
  
  
• IEnumConnectionPoints
  
  
• IConnectionPoint
  
  
• IEnumConnections
  
  

The IConnectionPointContainerinterface is implemented on the connectable object to indicate the existence of the outgoing interfaces.

It provides access to an enumerator subobject with the IEnumConnectionPointsinterface. It also provides access to all the connection point subobjects, each of which implements the IConnectionPointinterface.

The IConnectionPointinterface provides access to an enumerator subobject with the IEnumConnectionsinterface.

Each connection point is a separate subobject to avoid circular reference counting problems.

A connection point controls how many connections (one or more) it will allow in its implementation of IConnectionPoint::Advise. A connection point that allows only one interface can return E_NOTIMPL from the IConnectionPoint::EnumConnectionsmethod.

A client can use the IConnectionPointContainerinterface in these ways:

• To obtain access to an enumerator subobject with the IEnumConnectionPointsinterface. The IEnumConnectionPointsinterface can then be used to enumerate connection points for each outgoing IID.
  
  
• To obtain access to connection point subobjects with the IConnectionPointinterface for each outgoing IID.
  
  Through the IConnectionPointinterface, a client starts or terminates an advisory loop with the connectable object and the client's own sink. The client can also use the IConnectionPointinterface to obtain an enumerator object with the IEnumConnectionsinterface to enumerate the connections that it knows about.
  
  

To determine whether the platform supports this interface, see Determining Supported COM APIs.