According to WM_SCROLL command description, parameters SB_LINEDOWN (integer 1) and SB_LINEUP (integer 0) must be passed as wParam.
But in actuality the function only works if they're passed as the 3d parameter, that is lParam as per the doc, which leads me to believe that they have been misnamed. This of course applies not only to SB_LINEDOWN/UP.
Changing the value of the nominal wParam argument (the 4th one) in the animation doesn't affect the result.
As per the doc the 3d and 4th arguments are
lParam,wParamreaper.BR_Win32_SendMessage(identifier hwnd, integer msg, integer lParam, integer wParam)
According to
WM_SCROLLcommand description, parametersSB_LINEDOWN(integer 1) andSB_LINEUP(integer 0) must be passed aswParam.But in actuality the function only works if they're passed as the 3d parameter, that is
lParamas per the doc, which leads me to believe that they have been misnamed. This of course applies not only toSB_LINEDOWN/UP.Changing the value of the nominal
wParamargument (the 4th one) in the animation doesn't affect the result.