Autohotkey) Find WM_COMMAND parameter with Winspector

Step 1

If you do not already have Winspector,
Download & install Winspector from www.windows-spy.com/download/
Direct DL Link: Winspector_setup.exe ( 0.99 MiB )

Read this topic: Tutorial on posting messages to Windows



Step 2
Minimize all windows and Start your program.
> In this example I am using Windows Media Player




Step 3
Run Winspector. If you had chosen the default settings, then the path would be like
?:\Program Files\Winspector\WinspectorU.exe





Step 4
Close all the sub-windows with close buttons ( refer the Red arrows in above screenshot ) until
you have an empty window like below





Step 5

Select View > Window List





Step 6a

Click on the Window tab to make sure you are viewing the Window List





Step 6b

Browse the List and find your app. You can easily identify it with the Icon.
> In this case it is Windows Media Player
Select the Window from the list / Right click and select Messages...





Step 6c

Close the Window List and maximize the Message Window





Step 7a

You will see a plain window like below.
> Take a look at the Caption bar, WMP Skin Host is the ahk_class





Step 7b

Right click on the Client-area
1) make sure Filter messages is checked. If not check it.
2) Select Edit Message Filter...





Step 7c

By default, Winspector will monitor all the Window Messages,
Whereas, we need only it to monitor WM_COMMAND.
So click Filter all to remove all the Messages.





Step 7d

Select WM_COMMAND from the left list, double-click it to move it to the right list.





Step 7e

Click Ok button.





Step 8

Use alt-tab to move focus to Windows Media Player and perform the following:
1) Pull down Menu File > Open to open a media file
2) Pull down Play > Play/Pause to pause the media.
3) Pull down Play > Stop to stop the media





Step 9

Use alt-tab to move focus back to Winspector.
If you find that the window caption no longer points to "your Message capture window" ... and shows
something like SysShadow instead.. keep closing these sub-windows until "your window" appears in
the Caption.



In this example it is WMP Skin host and will appear as follows:



The highlighted integers are the required wParam for WM_COMMAND
Open = 57601
Play/Pause Toggle = 18808
Stop = 18809

From AHK, to control Play/Pause of WMP, the command would be