Cycling is too much fun


I have an application running on my lap top which should trap the WM_MOUSEWHEEL message allowing me to scroll backward and forward through my data.

However, the high word of wParam is always zero even though the low word reports the shift/alt/cap status correctly.

I have confirmed that my window has input focus and that GetSystemMetrics(SM_MOUSEWHEELPRESENT) returns true.

Any ideas why this should be

My only thought is that I'm using a laptop which has a local mouse pad and I also have a USB mouse. How does windows discriminate between the sources of wheel messages, or does it simply just 'OR' them together

Re: Windows WM_MOUSEWHEEL message

Danny Thorpe MSFT

Hi Chris,

You need to ask this question on one of the MSDN Win32 development forums. This Windows Live forum is for web service and web application development, primarily in the browser.



Re: Windows WM_MOUSEWHEEL message

Cycling is too much fun


Thanks for that.

So many forums..... so little time :-))