我截取了SCROLLBOX的WM_VSCROLL消息,怎么判断鼠标点击的是向上还是向下呢 ( 积分: 30 )

我截取了SCROLLBOX的WM_VSCROLL消息,怎么判断鼠标点击的是向上还是向下呢

信息在wParam参数里,具体查msdn

TWMVScroll(Message).ScrollCode<br>Value Meaning<br>SB_BOTTOM Scrolls&nbsp;to&nbsp;the&nbsp;lower&nbsp;right.<br>SB_ENDSCROLL Ends&nbsp;scroll.<br>SB_LINEDOWN Scrolls&nbsp;one&nbsp;line&nbsp;down.<br>SB_LINEUP Scrolls&nbsp;one&nbsp;line&nbsp;up.<br>SB_PAGEDOWN Scrolls&nbsp;one&nbsp;page&nbsp;down.<br>SB_PAGEUP Scrolls&nbsp;one&nbsp;page&nbsp;up.<br>SB_THUMBPOSITION Scrolls&nbsp;to&nbsp;the&nbsp;absolute&nbsp;position.&nbsp;The&nbsp;current&nbsp;position&nbsp;is&nbsp;specified&nbsp;by&nbsp;the&nbsp;nPos&nbsp;parameter.<br>SB_THUMBTRACK Drags&nbsp;scroll&nbsp;box&nbsp;to&nbsp;the&nbsp;specified&nbsp;position.&nbsp;The&nbsp;current&nbsp;position&nbsp;is&nbsp;specified&nbsp;by&nbsp;the&nbsp;nPos&nbsp;parameter.<br>SB_TOP Scrolls&nbsp;to&nbsp;the&nbsp;upper&nbsp;left.

多人接受答案了。