Implement a connection point

To implement a connection point using the Implement Connection Point Wizard, you must have created a project as an ATL COM application or as an MFC application that contains ATL support. You can use the ATL project wizard to create an ATL application, or add an ATL object to your MFC application to implement ATL support for an MFC application.

Once you create the project, to implement a connection point, you must first add an ATL object. See Adding objects and controls to an ATL project for a list of wizards that add objects to your ATL project.

A connectable object (that is, a source) can show a connection point for each of its outgoing interfaces. Each outgoing interface can be implemented by a client on an object (that is, a sink). For more information, see ATL connection points.

To implement a connection point:

1. In Class View, right-click the class name for your ATL object.

2. Choose Add from the shortcut menu, and then choose Add Connection Point to display the implement connection point wizard.

3. Select the connection point interfaces to implement from the appropriate type libraries and select Finish.

4. In Class View, examine the proxy classes created for each connection point. The classes appear as CProxyInterfaceName<T> and are derived from IConnectionPointImpl.

5. Double-click the connection point class to display the definition of the connection point's class.

   • If you implement a connection point for your own project's interface, the following definition appears:

     template< class T >
     class CProxyInterfaceName :
     public IConnectionPointImpl< T, &IID_InterfaceName >
     {
     public:
     };
     

   • If you implement a local interface, methods and properties appear in the class body.

   • If you implement a connection point for another interface, the definition includes the interface's methods, each preceded by Fire_.

In this section

• Implement connection point wizard

Implement connection point wizard

This wizard implements a connection point for a COM object. A connectable object (that is, a source) can show a connection point for its own interfaces or for any outgoing interface. MSVC and Windows both provide type libraries that have outgoing interfaces. Each outgoing interface can be implemented by a client on an object (that is, a sink).

For more information, see ATL connection points.

• Available type libraries

  Displays the available type libraries holding the interface definitions for which you can implement connection points. Select the ellipsis button to locate a file that has the type library to use.

• Location

  Displays the location of the type library currently selected in the Available type libraries list.

• Interfaces

  Displays the interfaces whose definitions are held in the type library currently selected in the Available type libraries box.

  Transfer button	Description
  >	Adds to the Implement connection points list the interface name currently selected in the Interfaces list.
  >>	Adds to the Implement connection points list all interface names available in the Interfaces list.
  <	Removes the interface name currently selected in the Implement connection points list.
  <<	Removes all interface names currently listed in the Implement connection points list.

• Implement connection points

  Displays the names of the interfaces for which you implement connection points when you select Finish.