COM Connection Points

1. COM Connection Points 主講人：虞台文

2. Content • The Client-Object-Sink Relationship • IConnectionPointContainer &IConnectionPoint • Implementation using ATL/COM

3. COM Connection Points The Client-Object-Sink Relationship

4. Connectable Object Sink The Process of Connecting Source & Sink Client passes sink interface pointer to connectable object. Client Connectable object calls sink when appropriate.

5. Client Sink Connectable Object Client Sink Sink Client Sink One-to-Many Relationship

6. Connectable Object Connectable Object Connectable Object Client Sink Many-to-One Relationship

7. COM Connection Points IConnectionPointContainer &IConnectionPoint

8. Connection Point Container Connection Point 1 Connection Point 2 Connection Point n IConnectionPointContainer &IConnectionPoint IConnectionPointContainer IConnectionPoint IConnectionPoint . . . IConnectionPoint

9. IConnectionPointContainer interface IConnectionPointContainer : IUnknown { HRESULT EnumConnectionPoints( IEnumConnectionPoints **ppEnum) = 0; HRESULT FindConnectionPoint(REFIID riid, IConnectionPoint **ppCP) = 0; };

10. IConnectionPoint interface IConnectionPoint : IUnknown { HRESULT GetConnectionInterface(IID *pIID) = 0; HRESULT GetConnectionPointContainer( IConnectionPointContainer **ppCPC) = 0; HRESULT Advise(IUnknown *pUnk, DWORD *pdwCookie) = 0; HRESULT Unadvise(DWORD dwCookie) = 0; HRESULT EnumConnections(IEnumConnections **ppEnum) = 0; };

11. COM Connection Points Implementation using ATL/COM

12. Step1. Create ATL/COM Project

13. Step1. Create ATL/COM Project

14. Step2. Create ATL Object

15. Step2. Create ATL Object

16. Step2. Create ATL Object

17. Step2. Create ATL Object

18. Step2. Create ATL Object

19. Step2. Create ATL Object

20. Step2. Create ATL Object

21. Step3. Modification of IDL // Timer.idl : IDL source for Timer.dll . . . . . . . . . . . . . . . . . . . . library TIMERLib { importlib("stdole32.tlb"); importlib("stdole2.tlb"); [ uuid(A1EE119D-1107-4BB9-B23A-2D338F7F955F), helpstring("_IPeriodicTimerEvents Interface") ] dispinterface _IPeriodicTimerEvents { properties: methods: }; [ uuid(FB1C62DE-5499-4C69-BC79-3EC6D5260D05), helpstring("PeriodicTimer Class") ] coclass PeriodicTimer { [default] interface IPeriodicTimer; [default, source] dispinterface _IPeriodicTimerEvents; }; };

22. Step3. Modification of IDL // Timer.idl : IDL source for Timer.dll . . . . . . . . . . . . . . . . . . . . library TIMERLib { importlib("stdole32.tlb"); importlib("stdole2.tlb"); [ uuid(A1EE119D-1107-4BB9-B23A-2D338F7F955F), helpstring("_IPeriodicTimerEvents Interface") ] interface _IPeriodicTimerEvents : IUnknown { }; [ uuid(FB1C62DE-5499-4C69-BC79-3EC6D5260D05), helpstring("PeriodicTimer Class") ] coclass PeriodicTimer { [default] interface IPeriodicTimer; [default, source] interface _IPeriodicTimerEvents; }; };

23. Step4. Add Properties and Methods

24. Step4. Add Properties and Methods

25. Step4. Add Properties and Methods

26. Step4. Add Properties and Methods

27. Step4. Add Properties and Methods

28. Step4. Add Properties and Methods

29. Step4. Add Properties and Methods

30. Step4. Add Properties and Methods

31. Step4. Add Properties and Methods

32. Step4. Add Properties and Methods

33. Step4. Add Properties and Methods

34. Step4. Add Properties and Methods

35. Step5. Build Type Library

36. Step5. Build Type Library

37. Step5. Build Type Library

38. Step6. Implement Connection Point

39. Step6. Implement Connection Point

40. Step7. Detail the Source Code See the Source Code for detail of other implementation.

41. Demonstration

42. Exercise • Implement an alarm clock object using ATL. In this COM object, you can set the alarm time, and the object will notify its sink when the time is up.