Windows 8 WM_POINTER vs WM_TOUCH

Question

The only information I can find on WM_POINTER is this talk and the accompanying slides: http://channel9.msdn.com/Events/BUILD/BUILD2011/APP-186T

In this other MSDN thread (http://social.msdn.microsoft.com/Forums/en-BZ/winforms/thread/ae834a88-2cdf-4bc7-89f3-19fc4c288610), Rob Caplan says "At a native level for desktop apps, the Windows 7 WM_TOUCH and WM_GESTURE ... are supplanted in Windows 8 by the WM_POINTER* messages."

This makes it sound to me as though WM_TOUCH and WM_GESTURE messages cannot be used at all in Win 8 and you must rewrite applications to use WM_POINTER. In the talk I linked above, Reed's explanation gave me the impression that WM_TOUCH and WM_GESTURE would still be available, but new applications are encouraged to go the WM_POINTER route. Which is it? I have a WM_TOUCH application I'm troubleshooting in Win8 and I'd like to know if my trouble could be caused by dropped support for WM_TOUCH.

Also, where can I find more information on WM_POINTER? I realize Win8 isn't out for some months, but with the push MS is making on touch, I'd like to see some better documentation.

Answer 1

The legacy messages (WM_TOUCH and WM_GESTURE) are still available. Your existing application should run without any changes.

You can find documentation on the WM_POINTER* family of messages in the User Input Message Reference on MSDN. Note that there is no "WM_POINTER" message. There are a number of messages starting with WM_POINTER: WM_POINTERUP, WM_POINTERDOWN, WM_POINTERUPDATE, etc. The individual messages topics are worth a read and have a lot of explanation and sample code.

--Rob

Answer 2

Thanks very much, Rob. Searching for WM_POINTER does not lead to that page, though it's what I was looking for.

Answer 3

You often need to search on the actual message names. If you can't remember them a useful trick is to search the header files to get the full names:

--Rob