'SCROLLBARINFO' : undeclared identifier

MFC 窗口加上滚动条，定义其，使用滚轮响应函数如下，怎么出错。。。。？？？

BOOL Caaaa::OnMouseWheel(UINT nFlags, short zDelta, CPoint pt)
{
// TODO: Add your message handler code here and/or call default
SCROLLBARINFO siInfo;
GetScrollInfo(SB_VERT,&siInfo);
int nMin,nMax,nThumbWidth;
nMin=siInfo.nMin;
nMax=siInfo.nMax;
nThumbWidth=siInfo.nPage;
int nPos=GetScrollPos(SB_VERT);
if (zDelta)
{
if (nPos==0)
{
return true;
}
SetScrollPos(SB_VERT,nPos-6);
ScrollWindow(0,6);
}
else
{
if ((nPos+nThumbWidth>=nMax))
{
return true;
}
SetScrollPos(SB_VERT,nPos-6);
ScrollWindow(0,-6);
}
return CDialog::OnMouseWheel(nFlags, zDelta, pt);
}

error:
D:\vc+++\窗口\aaaa.cpp(72) : error C2065: 'SCROLLBARINFO' : undeclared identifier
D:\vc+++\窗口\aaaa.cpp(72) : error C2146: syntax error : missing ';' before identifier 'siInfo'
D:\vc+++\窗口\aaaa.cpp(72) : error C2065: 'siInfo' : undeclared identifier
D:\vc+++\窗口\aaaa.cpp(75) : error C2228: left of '.nMin' must have class/struct/union type
D:\vc+++\窗口\aaaa.cpp(76) : error C2228: left of '.nMax' must have class/struct/union type
D:\vc+++\窗口\aaaa.cpp(77) : error C2228: left of '.nPage' must have class/struct/union type
执行 cl.exe 时出错.

SCROLLBARINFO应该是SCROLLINFO吧？

你好！ 我也是这个问题 但是确实有SCROLLBARINFO这个结构体 打字不易，采纳哦！