How to create a shell extension using IExplorerCommand for Windows 11, 10, 8, and 7?

David Izada Rodriguez 46

After reading Microsoft's documentation, Raymond Chen's blog, NanaZip implementation, and TortoiseSVN/TortoiseGit implementations, I created a "modern" shell extension implementing IClassFactory, IExplorerCommand, and IObjectWithSelection.
I also implemented several other interfaces but finally dropped them because they were unused.
When selecting two files, my context menu should appear like this:

It works correctly after selecting both files and clicking Shift-F10 (that is, on the "Show More Options" submenu).
But it cannot render the "using >" submenu on the top-level menu.

I tried the extension on Windows 7, registering the single root command (implementing IExplorerCommand and IObjectWithSelection), and it works as expected.

Assuming that Windows 11 will not accept over one submenu, the only solution is to use a separator and render the submenu items after it.
In my case, it means to declare CompareFilesUsing as a separator, returning empty values for Title and Icon and ECF_ISSEPARATOR for GetFlags.
Of course, that should be only for Windows 11 on the top-level menu (how to know that is the case?).
In my case, after making the necessary changes, I got the following:

There is something wrong here. There is no ">" announcing the submenu; the separator is just a blank line.
Is that correct? If not, what is happening?

How can my instances work under "Show More Options" and not on the top-level menu?

I have extensive logging in my extension, and I noticed that, even when Explorer uses the same DLL and instances, it follows different strategies for discovering the structure of the context menu provided by the extension. I'm attaching both logs for the command "Compare Files".
268352-tlm-comparefiles.txt => executing the command from the top-level Windows 11 menu
268266-smo-comparefiles.txt => executing the command from the "Show more options" submenu.

Analyzing the logs, it is noticeable that on the top-level menu, Explorer requests two instances of the root command.
This is part of my AppXManifest.xml:

  <Extensions>  
    <com:Extension Category="windows.comServer">  
      <com:ComServer>  
        <com:SurrogateServer DisplayName="Beyond Compare shell extension">  
          <com:Class Id="812BC6B5-83CF-4AD9-97C1-6C60C8D025C5" Path="BcShellEx64.dll" ThreadingModel="STA" />  
        </com:SurrogateServer>  
      </com:ComServer>  
    </com:Extension>  
    <desktop4:Extension Category="windows.fileExplorerContextMenus">  
      <desktop4:FileExplorerContextMenus>  
        <desktop5:ItemType Type="*">  
          <desktop5:Verb Id="AnyFile"               Clsid="812BC6B5-83CF-4AD9-97C1-6C60C8D025C5" />  
        </desktop5:ItemType>  
        <desktop5:ItemType Type="Directory">  
          <desktop5:Verb Id="AnyFolder"             Clsid="812BC6B5-83CF-4AD9-97C1-6C60C8D025C5" />  
        </desktop5:ItemType>  
      </desktop4:FileExplorerContextMenus>  
    </desktop4:Extension>  
  </Extensions>

As my extension accepts files and folders, I had to declare my COM server and the extension category (fileExplorerContextMenus) with two verbs.
I don't know if that is why Explorer spawns two instances, but under "Show More Options," Explorer creates only one instance, while the top-level menu creates two (and uses only one).

David Izada Rodriguez 46 Reputation points

2022-12-07T19:56:58.95+00:00

My extension is written in Embarcadero Delphi 11.2 (Alexandria)
Roy Li - MSFT 33,501 Reputation points Microsoft Vendor

2022-12-08T01:15:22.323+00:00

Could you please tell me what kind of application that you are developing? Is it a Win32 desktop application or a Windows app SDK application or other types of application?
David Izada Rodriguez 46 Reputation points

2022-12-08T04:03:37.307+00:00

It is a Win32 application, a 64-bits dynamic link library.
I used a sparse package (published part of it with the extensions) for installing the extension on Windows 11.
Most of the commands are dynamic, depending on previous commands (modifying the registry) and the selected items.
Xiaopo Yang - MSFT 12,726 Reputation points Microsoft Vendor

2022-12-08T05:13:46.22+00:00

Have you tried Microsoft official samples SparsePackages introduced in Extending the Context Menu and Share Dialog in Windows 11 and ExplorerCommandVerb?
David Izada Rodriguez 46 Reputation points

2022-12-08T12:10:25.593+00:00

Yes, I used all Microsoft samples related to IExplorerCommand.
Read all the documentation available.
The extension I created is the result of 6 months of work.
Once I exhausted Microsoft's Documentation, I looked everywhere and found some implementations.
TortoiseSVN and TortoiseGit share the exact implementation (simpler than what I require), and it doesn't work as well as their previous one using IContextMenu.
NanaZip implemented a simple dynamic menu, and I followed their design.
In addition to the extensive logging I added to my extension, I simulated a host (acting as File Explorer) loading the extension, creating the class factory, getting the root instance, loading the full menu, and invoking a command.
That allowed me to debug the extension and avoid a more complex scenario easily.
My concrete issue is that the same extension working under "Show more options" on Windows 11 fails to show the deepest submenu on the top-level menu on Windows 11.
David Izada Rodriguez 46 Reputation points

2022-12-09T13:24:20.637+00:00
Comparing the logs generated on Windows 11 top-level menu and under "Show more options," I noticed they use different algorithms for getting the extension context menu tree:

Top-Level Menu (TLM):

Create an instance of IExplorerCommand

GetState

GetTitle

GetIcon

GetFlags

If flag was ECF_HASSUBCOMMANDS, EnumSubCommands and visit them using Enum.Next(1)

For each visited command, repeat the sequence from step 2

Show More Options (SMO):

Create an instance of IExplorerCommand

SetSelection (IObjectWithSelection)

GetFlags

GetCanonicalName

GetToolTip

GetTitle

GetIcon

GetState

If flag was ECF_HASSUBCOMMANDS, EnumSubCommands and visit them using Enum.Next(1)

For each visited command, repeat the sequence from step 2

On TLM they create an instance they don't use later. I don't know why.
David Izada Rodriguez 46 Reputation points

2022-12-09T15:05:48.39+00:00

I concluded that it is a requirement or limitation of the new context menu on Windows 11.
The main goal of the latest changes is to streamline and simplify the context menu.
According to NanaZip's developer, he discovered that Windows 11 limited the number of items on the context menu to 16.
But he also said that it was possible to extend that number by adding separators.
In other words, if you cannot create a submenu, you could create a separator and list the submenu items as additional items on that level.
I'll try that solution.
It is incredibly obscured; it should be part of the documentation of IExplorerCommand.
David Izada Rodriguez 46 Reputation points

2022-12-12T15:54:35.943+00:00

Well, I lost all hope to render my context menu with two levels and tried using a separator.
On Windows 11, top-level menu, the separator item is just an empty row.
On "Show More Options", I get the correct behavior.

Is it my impression, or the new Windows 11 "native" implementation of IExplorerCommand is flawed?
David Izada Rodriguez 46 Reputation points

2022-12-13T15:54:57.173+00:00

The last issue, not showing the separator on the top-level menu, was solved by returning a nullptr on GetTitle.
I was returning an empty string, and it worked on "Show More Options", but not on the top-level menu.

Now, my top-level menu is different, and not as clear to the customers as the previous menu (using a submenu for the viewers), but it works.

Microsoft's documentation should be slightly improved to allow everyone to update their extensions to Windows 11.
Xiaopo Yang - MSFT 12,726 Reputation points Microsoft Vendor

2022-12-14T01:39:50.767+00:00

Hello @Anonymous , you can send feedback about the concern and edit the documentation of IExplorerCommand by
David Lowndes 4,721 Reputation points

2022-12-19T21:32:50.56+00:00

While I can understand your persistence in trying to get this to work as you'd hope it would; as a user of Beyond Compare I wouldn't be too concerned about supporting the Win11 context menu. Most people I know are thankful when I tell them the registry key to disable it so they never have to see it again. I suspect much of your user base may already have disabled the Win11 context menu.
David Izada Rodriguez 46 Reputation points

2023-01-21T23:32:38.8066667+00:00

After finishing the extension and testing it under different scenarios, we discovered another issue:

When right-clicking an object in a temporary device (like a smartphone connected through USB), the IShellItemArray the extension receives requires special treatment to get ShellItem.GetDisplayName. The returned name does not include a path to open it, just the name.

Instead of receiving an SFGAO_FOLDER or SFGAO_FILESYSTEM, we receive an SFGAO_STREAM.

How can we get a path to open the file or folder?
Eddie 6 Reputation points

2023-01-22T16:21:59.11+00:00

@Anonymous , I recommend you start a new thread for this second question. This current thread has an accepted answer and is unlikely to attract much attention.
support onmicrosoft 0 Reputation points

2024-12-25T13:45:15.8866667+00:00

@Anonymous do you have a Delphi tutorial how to make the IExplorerCommand working? ... or useful hints :)

Thanks,

Uli

Accepted answer

Eugene Mayevski (Allied Bits) 90 Reputation points

2023-01-18T07:37:20.22+00:00

Assuming that Windows 11 will not accept over one submenu

Yes, this is mentioned in MSDN, in one of the topics on IExplorerCommand.
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3 people found this answer helpful.
David Lowndes 4,721 Reputation points

2023-01-19T00:17:33.65+00:00

A link to the article would be useful!

David Izada Rodriguez 46 Reputation points

2023-01-19T00:37:02.9066667+00:00

@David Lowndes If you read my initial post and my "solution," you will have most of the information Microsoft published about the new context menu on Windows 11. I may have missed the two-level restriction on the top-level menu, but my workaround was an effective solution.

My current implementation added Directory\Background to activate the context menu when right-clicking the background of any folder on Windows Explorer or the desktop.

Microsoft's documentation is not as comprehensive as it was in the past.

I used ideas from NanaZip, TortoiseSVN/TortoiseGit, and a few other open-source projects to achieve my implementation.

David Lowndes 4,721 Reputation points

2023-01-19T09:15:54.7066667+00:00

You wrote:

Assuming that Windows 11 will not accept over one submenu
Yes, this is mentioned in MSDN, in one of the topics on IExplorerCommand.

Where is it mentioned in MSDN documentation?

Eric Zhang 5 Reputation points

2023-11-22T08:50:27.45+00:00

To save time for future people, that "one of the topics" on submenu restrictions is IExplorerCommand::EnumSubCommands, in the "Remarks" section:

Subcommands which themselves have subcommands are not supported by Windows Explorer. When a command has its own subcommands, it must designate this status by specifying ECF_HASSUBCOMMANDS in the IExplorerCommand::GetFlags call.
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David Izada Rodriguez 46 Reputation points

2024-12-25T13:58:47.69+00:00

I want to conclude this thread by informing everyone of my last decision.

Despite the simplicity of IExplorerCommand, if activating the context menu requires awareness about the selection, must work on unsupported devices, or any other not-so-simple scenario, it is better to use IExplorerCommand for the top-level menu and IContextMenu for everything else.

Microsoft's implementation of IContextMenu is too simplistic and covers just a fraction of what was possible with IContextMenu.
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Myles Jeffery 0 Reputation points

2024-12-29T15:31:55.4+00:00

How do you get a separator to show? No matter which combinations I try of GetState/GetTitle/GetFlags, either the separator does not show at all, or it shows as a menu item with text. This is on Windows 11 with IExplorerCommand.

David Izada Rodriguez 46 Reputation points

2024-12-29T18:11:51.28+00:00

When you return the menu item, you must return its flag as MF_SEPARATOR. The IContextMenu contains a list of items, and each one will be queried for several reasons (to see if it is active, what kind of item it is, execute it, etc.).

Myles Jeffery 0 Reputation points

2024-12-29T19:44:07.62+00:00

Thanks for the reply, I appreciate it. I should clarify that its the GetFlags method on IExplorerCommand I am referring to, not IContextMenu. I return ECF_ISSEPARATOR but it does not show the menu item as a separator. I think that this is not currently supported in Windows 11 context menu to show a separator.
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How to create a shell extension using IExplorerCommand for Windows 11, 10, 8, and 7?

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