I am having trouble getting the WM_MOUSEWHEEL event handler written so that my program will compile. Apparently WM_MOUSEWHEEL is not a constant that's been defined in any of my header files, which I find odd. The errors I'm getting are: (119): error C2065: 'WM_MOUSEWHEEL' : undeclared identifier (119): error C2051: case expression not constant I am using Microsoft Visual C++ .NET 2003. I thought that maybe I would have to update the Platform SDK, which I thought I did, but it didn't help. What I did to update the Platform SDK was the following: 1) Download the latest Platform SDK (MS Platform SDK for Windows Server 2003 SP1) from microsoft.com. 2) Install the SDK to C:\Program Files\Platform SDK 3) Overwrite the folder "C:\Programs Files\MSVS .NET 2003\VC7\PlatformSDK with the folder "C:\Program Files\Platform SDK" and rename it accordingly. It's sort of a "hack" way to do it, and might have not worked.

Thanks, I'll do a search on it. I actually tried Google several times, and the MSDN, but apparently I wasn't thorough enough or didn't quite know what I was looking for. In the meantime, I'll use your hack until I find the proper solution. Works well enough for test runs!

Ah, searching finally pays off. I present the following, for interested parties:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnwui/html/BestPracticesforSupportingMicrosoftMouseandKeyboardDevices.asp

WM_MOUSEWHEEL is only defined in later versions of windows. To have the identifier defined you'll need to put the line



before you include windows.h (or something like objbase.h etc) then the mouse wheel macros are defined properly and your code will compile.

Source wins. Thanks. It turns out that my solution defining WM_MOUSEWHEEL as 0x020e didn't work anyway.