For a long time, I've been looking for a class in .NET that has functionality that makes it so that the operating system thinks there is a file (or directory, or both, etc) at a particular location - but all hooks are passed to a function (or event?) in code.
Example:
If I browse to "x:\fake_directory\" I will see a file there, "fake_file.txt". If I double click on the file, Notepad.exe will launch and the file contents would say "Hello World". "Hello World" would come from my c# code.
Example of what I hope the class can do (maybe this will explain it better):
VirtualFile.Register("c:\my_file.txt",
delegate { return Encoding.Ascii.GetBytes("Hello World"); });
That's, of course, a simplified version of what I'm looking for... but hopefully you get the idea.
The reason why this is 100% needed is to work with legacy code or proprietary (and very old legacy garbage) systems that require reading and writing to the file system to communicate.
I believe Dokan would fit your needs for a virtual file system library. Dokan is written in c++ but there is a .NET library to interact.
On the other hand, i believe IPC would be better to achieve the needed functionality for which you gave an example in the comments.