How can I add items to Windows Shell (rightclick)?

Question

I'm going to make a desktop application that will run in the background, meaning no visible window, and I'd like an option called: "Upload Text" to appear when a user right clicks a file.

Can someone point me in the right direction? I also have to make sure that if someone wants to uninstall the program at any point, that the shell modification is also cleanly eliminated.

The app will run Windows XP, Windows Vista and Windows 7. How different are these OS's in handling my shell dilema?

Thank you!

Answer 1

You could add your app to the SendTo folder.

Answer 2

This is a shell extension. You've tagged this question with the C# tag; you should know that writing shell extensions in a managed language is strongly discouraged:

Unfortunately unmanaged C++ is really the only way to go here.

Writing in-process shell extensions in managed code is actually a very dangerous thing to do because it has the effect of injecting your managed code (and the .NET Framework) into every application on the machine that has a file open dialog.

The problems occur because only one version of the .NET Framework can be loaded in a process at any given time (other shared components such as java and msxml have the same property and thus the same restriction).

If you write your shell extension using the 2.0 .NET Framework and an application built with the 1.1 .NET Framework uses a file open dialog, your shell extension will fail because it can not run on an earlier version. Things can get even worse if your shell-extension manages to get loaded in a process before another applications managed code does: your extension may force an existing application onto a different runtime version than the one it was expecting and cause it to fail.

Because of these problems we strongly recomend against using any single-instance-per-process runtime or library (such as the .NET Framework, java, or msxml) in an in-process shell extension.

That said, people have done it.

Here's a guide to creating shell extensions, using C++.

Answer 3

What about a stand-alone program using SendTo?

Install the exe to "Program Files\mycompany\myprogram" and a shortcut to the exe into the SendTo folder. Then when a user right clicks on a file, selects SendTo, and then selects your program, your exe will be executed by Windows and the full path to the filename will be passed in via argv[1]. If they select n files they will be in argv[1]..argv[n].

If you want your program to be invisible then do not make the default form visible. You could optionally place an icon in the tray so the user could double click on it to see the upload progress. When the upload of argv[1] is complete, process argv[2]...argv[n] if they exists and exit. To cleanly uninstall, remove your program and the shortcut from the SendTo folder.