Click here to Skip to main content
13,559,658 members
Click here to Skip to main content
Add your own
alternative version


38 bookmarked
Posted 23 May 2004

Microsoft Outlook Add-in Tutorial - 2: Addding Events to Button

, 11 Jun 2004
Rate this:
Please Sign up or sign in to vote.
This adds an Event Handler to the Button added in first tutorial.


Adding an Event Handler for the Button created in previous tutorial

In the previous tutorials, we have seen how to add a toolbar and thus create a button in Microsoft Outlook. Now, in this tutorial, we will see how to invoke an event handler for the button, or in terms of COM, how to advise the Button event!.

The idea behind this tutorial is simple, we need to display a message box saying, "Button Clicked", when we click on the button created. For this, we have to capture the Button Click Event, i.e., CommandBar Events. The disp interface responsible for this is _CommandBarButtonEvents. So now, if we implement this sink interface that will be called by the event source, then our job is over.


So, here we have to create a connection point between our button and interface in simple words. The IDispEventSimpleImpl<> interface provides the connection points for an ATL COM Object. It is also used to implement an event dispinterface. Now, we have to derive our class from this interface. This is done as follows:

<PRE lang=mc++>class ATL_NO_VTABLE CAddin : public CComObjectRootEx<CComSingleThreadModel>, public CComCoClass<CAddin, &CLSID_Addin>, public IDispatchImpl<IAddin, &IID_IAddin, &LIBID_OUTLOOKADDINLib>, public IDispatchImpl<_IDTExtensibility2, &IID__IDTExtensibility2, &LIBID_AddInDesignerObjects>, //the derivation is done here public IDispEventSimpleImpl<1,CAddin, &__uuidof(Office::_CommandBarButtonEvents)> Parameters:
  1. The first parameter is a unique identifier for the source object.
  2. The second parameter is the user's class, so here we have CAddin.
  3. The third parameter is pointer to IID of the event dispinterface by this class.
  4. Here our dispinterface is Office::_CommandBarButtonEvents. For help, please refer Microsoft Outlook Object Model.

A Simple Shortcut:

Now, we do a simple shortcut to make our job easier. We add this code before the constructor in our file:

//the added code is here
 typedef IDispEventSimpleImpl</*nID =*/ 1, 

    CAddin, &__uuidof(Office::_CommandBarButtonEvents)> CommandButton1Events;

As we can see, this can help in advising our sink since we are doing typedef here. If you get confused here, please do feel free to proceed to the next step.

Sink Entry:

In order to move with sinks, we have to have entries for our event notifications to be handled by their proper functions as we have for Messages in MFC and Win32.

So, we need to enter the SINK ENTRY as follows after END_COM_MAP() macro.

SINK_ENTRY_INFO(1, __uuidof(Office::_CommandBarButtonEvents),0x01, 
                               OnClickButton, &OnClickButtonInfo)

We have specified our unique identifier, IID identifying the dispatch interface, dispid identifying the specified event, name of the event handler function, and the last parameter corresponds to type information. This is provided in the form of ATL_FUNC_INFO structure. We do it in Addin.cpp file.

_ATL_FUNC_INFO OnClickButtonInfo = 

Setting up our CallBack:

  1. We define our callback as follows:
    void __stdcall 
          OnClickButton(IDispatch * /*Office::_CommandBarButton**/ Ctrl, 
          VARIANT_BOOL * CancelDefault); 
  2. Next would be our declaration of our OnClickButton function which is added at the top of Addin.h.
    extern _ATL_FUNC_INFO OnClickButtonInfo;
  3. The next and final step is to write our function! So, here is the function, in Addin.cpp.
    void __stdcall CAddin::OnClickButton(IDispatch* Ctrl, 
                                    VARIANT_BOOL * CancelDefault)
        MessageBox(NULL, "U Have Clicked Me, 
                                Friend", "OnClickButton", MB_OK);

That's it....we have completed our second tutorial of getting a message box when we press the looks so simple and sure it is.

Since this is my first step in writing tutorials, please do feel free to send your reviews to


  1. This tutorial was based on the idea of Amit Dey in his tutorial, Building an Office2K COM add-in with VC++/ATL.

    So all my thanks goes to Mr. Amit Dey who was 'the guru' for me to Add-ins.

  2. And I mention Igor Tandek of Microsoft Corporation for his great help in making me understand the Inner Concepts of Add-ins along with ATL COM.

A small request to Amit Dey....any contact number or address or mail-id?


This article has no explicit license attached to it but may contain usage terms in the article text or the download files themselves. If in doubt please contact the author via the discussion board below.

A list of licenses authors might use can be found here


About the Author

Software Developer
New Zealand New Zealand
Chakkaradeep, known as Chaks to his friends, hails from the Indian subcontinent.Having done his Masters in Software Engineering, he knows his way around a computer and has sound knowledge of Microsoft technologies.

Chaks is currently working as a Microsoft Developer @ New Zealand.

You can reach him via his blog -

You may also be interested in...

Comments and Discussions

GeneralDLL giving errors Pin
Cansu13-Nov-07 14:08
memberCansu13-Nov-07 14:08 

General General    News News    Suggestion Suggestion    Question Question    Bug Bug    Answer Answer    Joke Joke    Praise Praise    Rant Rant    Admin Admin   

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.

Permalink | Advertise | Privacy | Cookies | Terms of Use | Mobile
Web01 | 2.8.180527.1 | Last Updated 12 Jun 2004
Article Copyright 2004 by chakkaradeepcc
Everything else Copyright © CodeProject, 1999-2018
Layout: fixed | fluid