I have a .NET winform application that writes an XML data file, but I want the file to have a custom (dynamic) thumbnail when you view the file via Explorer.
To give an example, PDF files show a thumbnail (picture) in XP and Win7 when you set the View mode to Thumbnail. This also works for pictures.
Presumably the process would be similar to the PDF file, since I would assume Windows just looks for some kind of “I’m a thumbnail” record within the file.
I’m also aware of the saved thumbnail images that Windows caches for picture directories. I’ve seen these files on occasion, but never played with them.
Files don’t say they’re thumbnail. You need to write a Windows Explorer Shell handler that says, I have a thumbnail for this file type, and extracts the thumbnail.
As per the Microsoft answer in http://social.msdn.microsoft.com/forums/en-US/netfxbcl/thread/1428326d-7950-42b4-ad94-8e962124043e/ this has to be in C++ not .NET.
Check these:
http://www.shellplus.com/examples/thumbnail-image-handler-example.html
http://msdn.microsoft.com/en-us/library/cc144067(v=vs.85).aspx
Sample Google Query:
http://www.google.com.au/webhp?sourceid=chrome-instant&ie=UTF-8&ion=1&nord=1#hl=en&xhr=t&q=create+thumbnail+shell+handler&cp=0&pf=p&sclient=psy&nord=1&site=webhp&aq=f&aqi=&aql=&oq=create+thumbnail+shell+handler&pbx=1&fp=190c8307a70ec87c&ion=1