Question

I am trying to create a little helper application, one scenario is “file duplication finder”. What I want to do is this:

• I start my C# .NET app, it gives me an empty list.
• Start the normal windows explorer, select a file in some folder
• The C# app tells me stuff about this file (e.g. duplicates)

How can I monitor the currently selected file in the “normal” windows explorer instance. Do I have to start the instance using .NET to have a handle of the process. Do I need a handle, or is there some “global hook” I can monitor inside C#. Its a little bit like monitoring the clipboard, but not exactly the same…

Any help is appreciated (if you don’t have code, just point me to the right interops, dlls or help pages 🙂 Thanks, Chris

EDIT 1 (current source, thanks to Mattias)

using SHDocVw;
using Shell32;

public static void ListExplorerWindows()
{
    foreach (InternetExplorer ie in new ShellWindowsClass())
        DebugExplorerInstance(ie);
}

public static void DebugExplorerInstance(InternetExplorer instance)
{
    Debug.WriteLine("DebugExplorerInstance ".PadRight(30, '='));
    Debug.WriteLine("FullName " + instance.FullName);
    Debug.WriteLine("AdressBar " + instance.AddressBar);
    var doc = instance.Document as IShellFolderViewDual ;
    if (doc != null)
    {
        Debug.WriteLine(doc.Folder.Title);
        foreach (FolderItem item in doc.SelectedItems())
        {
            Debug.WriteLine(item.Path);
        }
    }
}

Answer 1

You can do this with the shell automation interfaces. The basic process is to

1. Run Tlbimp on Shdocwv.dll and
   Shell32.dll (or directly add a
   reference from VS).
2. Create an
   instance of the ShellWindows
   collection and iterate. This will
   contain both Windows Explorer and
   Internet Explorer windows.
3. For
   Windows Explorer windows, the
   IWebBrowser2.Document property will
   return a IShellFolderViewDual
   reference.
4. The IShellFolderViewDual
   has a SelectedItems method you can
   query and an event for changes you
   can handle.