How can I implement an interactive tutorial inside an app?

I h开发者_如何学运维ave C# add-in for Word and would like to implement an interactive tutorial like games usually have. I'd like to somehow highlight (maybe by circling) certain visual elements and display text boxes that describe what the element does. For example, say the add-in is a generic workflow editor. I'd like to show to the user, step by step, what needs to be done by visually selecting elements and explaining what they do and what options (s)he has. My first question is: can this be done in C#? My second question is how? :) I suppose I'd have to get the positions of said visual elements and then draw an image on top but I don't know how that could be done.

I'm a bit disappointed that not even a single member of the Stack Overflow community took the the time to at least give a hint about this. But such is life and I'm just going to share my findings here because I'm certain someone else will benefit from them.

To be able to do an interactive tutorial you need three things:

• a method to find where a control is located in terms of screen coordinates
• a method to point the user to the control by highlighting it or surrounding it with a red line for example.
• a method to do its default action (ie: click a button).

In other words, the idea is to have some sort of window with text describing a control and some graphical way of indicating the control in the app. Optionally, the window could provide something like a ShowMe button which shows the user how to use the control by taking control of the mouse and keyboard.

This is trivial when the controls are made by yourself and thus have source code access. However, when doing such a thing for a black box app such as Word you can use the Windows IAccessible interface. Searching for that with your favorite search engine will yield everything you need to understand it and use it. IAccessible allows one to do many things but most importantly it can get a control's position and can also do the default action.

Having sorted out these things the next step is to figure out how to graphically point out the control. There are many ways to do this but in my case I chose to surround it with a red rectangle. I did this by creating an invisible, borderless form with an empty red rectangle on it. Having the control's position and size, I had no problems placing the aforesaid form over the control.

So there you have it. I laid out the building blocks that one needs to make an interactive tutorial for any app.