Find out what process registered a global hotkey? (Windows API)

Question

As far as I've been able to find out, Windows doesn't offer an API function to tell what application has registered a global hotkey (via RegisterHotkey). I can only find out that a hotkey is registered if RegisterHotkey returns false, but not who "owns" the hotkey.

In the absence of a direct API, could there be a roundabout way? Windows maintains the handle associated with each registred hotkey - it's a little maddening that there should be no way of getting at this information.

Example of something that likely wouldn't work: send (simulate) a registered hotkey, then intercept the hotkey message Windows will send to the process that registered it. First, I don't think intercepting the message would reveal the destination window handle. Second, even if it were possible, it would be a bad thing to do, since sending hotkeys would trigger all sorts of potentially unwanted activity from various programs.

It's nothing critical, but I've seen frequent requests for such functionality, and have myself been a victim of applications that register hotkeys without even disclosing it anywhere in the UI or docs.

(Working in Delphi, and no more than an apprentice at WinAPI, please be kind.)

Answer 1

One possible way is to use the Visual Studio tool Spy++.

Give this a try:

1. Run the tool (for me, it's at C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\Tools\spyxx_amd64.exe)
2. In the menu bar, select Spy -> Log messages... (or hit Ctrl + M)
3. Check All Windows in System in the Additional Windows frame
4. Switch to the Messages tab
5. Click the Clear All button
6. Select WM_HOTKEY in the listbox, or check Keyboard in Message Groups (if you're OK with more potential noise)
7. Click the OK button
8. Press the hotkey in question (Win + R, for example)
9. Select the WM_HOTKEY line in the Messages (All Windows) window, right click, and select Properties... in the context menu
10. In the Message Properties dialog, click the Window Handle link (this will be the handle for the window that received the message)
11. Click the Synchronize button on the Window Properties dialog. This will show the window in the main Spy++ window treeview.
12. On the Window Properties dialog, select the Process tab
13. Click the Process ID link. This will show you the process (In my Win + R case: EXPLORER)