DDD Using and Extending Excel with Visual Studio A high level discussion of the main options Simon Murphy Developer – Codematic Ltd – Excel Development.

DDD Agenda Background Patterns and technical options VSTO demo The main questions (how to choose) Automation v COM Add-ins Demos –Com Add-in –Automation Add-in Deployment Justification Summary & questions

DDD Background On-line confusion No (easy to find) succinct info from MS Mild panic after VB6 retirement (VB6 ~ VBA) Few books (changing rapidly) Why target Excel? –400 Million installations –Very powerful, very programmable client ~ 200 objects ~ 80 events ~ 200 enumerations ~ 4,500 methods and properties Note: this presentation pretty much ignores VBA

DDD Design Patterns Workbook with code behind Excel Add-in –COM Add-in –Automation Add-in Automation executable

DDD Working with Excel - The options VSTO (Visual Studio Tools for the Office System) COM Add-ins Automation Add-ins Standard automation projects –Open, Automate, use features and Close Excel –Excel 97 maybe earlier? XLL Add-ins –Native win32 DLLs (ie pretty much C++) –Excel 4.0 maybe earlier? –Still very relevant VBA Add-ins – Not discussed here

DDD VSTO Demo VSTO (Visual Studio Tools for the Office System) –Special VS template projects that incorporate strong office links. –Closest replacement for workbooks with embedded VBA. –Excel 2003 professional or better –VSTO 2003 US only VSTO 2005 any locale. –Locale still very much an issue for other.net developments

DDD 4 Big Questions 1.What version of Excel? 2.Function or Feature? 3.Application or Workbook Level? 4.Who initiates connection? Or Hosted v None Hosted

DDD 1. Which Version of Excel If Excel 2003 all options are possible Anything less than 2003 (professional) –VSTO (Visual Studio Tools for the Office System) is not possible Anything less than Excel XP –Automation Add-ins not possible Anything less than Excel 2000 –COM Add-ins not possible Total Office Installs – around 400M Excel Versions ~ 2003 – 15% - 60M 2002 – 35% - 140M 2000 – 40% - 160M 1997 – 10% - 40M

DDD 2. Function or Feature? Function (as in worksheet function) –Automation add-in Visual Studio 6 (generally VB6.0) Visual Studio.net VSTO not appropriate –XLL Best performance Feature –COM Add-in –VSTO –Standard automation

DDD 3. Application or Workbook Level? Application –COM Add-in –Automation Add-in –Standard automation project Workbook –VSTO –VBA

DDD 4. Who Initiates connection? Excel (hosted) –VSTO –COM Add-in –Automation Add-in Your application (not hosted) –Standard automation project

DDD Demo COM Add-in – load up events –Application level functionality –Excel 2000 or better –Visual Studio 5 >>

DDD Automation v COM Add-in Automation Add-ins are COM add-ins that can be called directly from a worksheet cell. COM Add-ins –Must Implement IDTExtensibility2 –Generally load on Excel start up (can be changed) Automation Add-ins –May Implement IDTExtensibility2 (discouraged) –Loaded on demand only

DDD Demo Automation Add-in – Worksheet formula –Directly callable worksheet formulas –Excel XP (2002) or better –Visual Studio 5 >>

DDD Development & Deployment Excel is written in unmanaged C with COM interfaces for VBA and other apps. VBA/XLL has the easiest initial deployment (updates are more complex though) VSTO has the most flexible and overall easiest deployment (server or local) COM Add-ins & Automation Add-ins –standard COM local registry issues. –Should have a shim (Custom CLR loader)

DDD COM Shims What are they? –COM dll that loads Mscoree.dll which then loads our managed component –Excel>>COMSHIM>>Mscoree>>MyAddin.dll Why use them? –Security (code signing) –AppDomain Isolation Protect other apps from failures in our component Protect our component from other failures

DDD Why bother? Why change from the current VBA / COM approach? –Deployment and maintenance easier 1 version Write controlled location Cleaner tiered architecture –.net framework functionality –Visual studio.net IDE better than VBAIDE –Enterprise code reuse –.net security may be better than macro security?

DDD When to bother? Note: my personal guess only! Mainstream in 2007! Excel 12 due mid/late 2006 –Excel 12 is a genuine improvement VSTO 3 will probably match that time scale –Very likely to include more application level features Task panes, Add-ins, etc Approx 12 months to get reasonable uptake VBA will be looking very shabby by then VSTA (Visual Studio Tools for Applications) will have fully arrived.net framework should have reached saturation level.

DDD Resources

DDD Summary VSTO for modern workbook based solutions COM Add-ins for application level features Automation Add-ins for worksheet functions

DDD Finally Any questions? Simon Murphy – Excel Development.