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序号：64170 发表者：xiaogang_2000 发表日期：2003-12-09 11:19:29
<br>主题：为什么按下CONTROL和SHIFT键只在MouseMove消息中有效
<br>内容：为什么按下CONTROL和SHIFT键只在MouseMove消息中有效。<BR>如以下程序，这是为什么呀？<BR>我需要在左键按下时检测SHIFT键按下（比如要实现多选的功能），该怎么处理？<BR>void CDdeView::OnLButtonDown(UINT nFlags, CPoint point) <BR>{<BR>&nbsp;&nbsp;&nbsp;&nbsp;// TODO: Add your message handler code here and/or call default<BR>&nbsp;&nbsp;&nbsp;&nbsp;if (nFlags == MK_CONTROL)<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;TRACE(&#34;MK_CONTROL\n&#34;);<BR>&nbsp;&nbsp;&nbsp;&nbsp;else if (nFlags == MK_SHIFT)<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;TRACE(&#34;MK_SHIFT\n&#34;);<BR>&nbsp;&nbsp;&nbsp;&nbsp;else <BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;TRACE(&#34;no \n&#34;);<BR>&nbsp;&nbsp;&nbsp;&nbsp;<BR>&nbsp;&nbsp;&nbsp;&nbsp;CView::OnLButtonDown(nFlags, point);<BR>}<BR><BR>void CDdeView::OnMouseMove(UINT nFlags, CPoint point) <BR>{<BR>&nbsp;&nbsp;&nbsp;&nbsp;// TODO: Add your message handler code here and/or call default<BR>&nbsp;&nbsp;&nbsp;&nbsp;if (nFlags == MK_CONTROL)<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;TRACE(&#34;MK_CONTROL\n&#34;);<BR>&nbsp;&nbsp;&nbsp;&nbsp;else if (nFlags == MK_SHIFT)<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;TRACE(&#34;MK_SHIFT\n&#34;);<BR>&nbsp;&nbsp;&nbsp;&nbsp;else <BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;TRACE(&#34;no \n&#34;);<BR>&nbsp;&nbsp;&nbsp;&nbsp;<BR>&nbsp;&nbsp;&nbsp;&nbsp;CView::OnMouseMove(nFlags, point);<BR>}<BR><BR>[e-mail]<BR>qq:56700320 
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回复者：元元 回复日期：2003-12-09 13:24:53
<br>内容：OnLButtonDown（）中nFlags的值是MK_LBUTTON和MK_CONTROL或MK_SHIFT的组合，因为只要按下，就肯定会有MK_LBUTTON的值如果此时同是按下Ctrl的话，则nFlags的值就是MK_LBUTTON和MK_CONTROL的组合了；而OnMouseMove也可以是它们的组合，不过你只移动同时按住Ctrl键的时候，nFlags的值只是MK_CONTROL，这也就是你在程序中所看到的效果，如果你把OnLButtonDown（）改成如下<BR>if (nFlags &amp; MK_CONTROL)<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;TRACE(&#34;MK_CONTROL\n&#34;);<BR>&nbsp;&nbsp;&nbsp;&nbsp;else if (nFlags &amp; MK_SHIFT)<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;TRACE(&#34;MK_SHIFT\n&#34;);<BR>&nbsp;&nbsp;&nbsp;&nbsp;else <BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;TRACE(&#34;no \n&#34;);<BR>则可以检测到SHIFT键按下的信息
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<font color=red>答案被接受</font><br>回复者：元元 回复日期：2003-12-09 13:30:18
<br>内容：兄弟记得给我加分啦
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