subject_26775.htm

一些关于vc的问答

<p>
序号：26775 发表者：霏昀 发表日期：2003-01-05 12:27:15
<br>主题：关于宏定义和switch
<br>内容：#define LEFT 0<BR><BR>void main()<BR>{<BR>&nbsp;&nbsp;&nbsp;&nbsp; int i;<BR>&nbsp;&nbsp;&nbsp;&nbsp; ......<BR>&nbsp;&nbsp;&nbsp;&nbsp; switch(i)<BR>&nbsp;&nbsp;&nbsp;&nbsp; {<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;case LEFT:......<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;.......<BR>&nbsp;&nbsp;&nbsp;&nbsp; }<BR>&nbsp;&nbsp;&nbsp;&nbsp; .......<BR>}<BR><BR>通不过编译，why?
<br><a href="javascript:history.go(-1)">返回上页</a><br><a href=http://www.copathway.com/cndevforum/>访问论坛</a></p>
<hr size=1>
<blockquote><p>
回复者：tjhe 回复日期：2003-01-05 12:29:21
<br>内容：错误提示？？
<br>
<a href="javascript:history.go(-1)">返回上页</a><br><a href=http://www.copathway.com/cndevforum/>访问论坛</a></p></blockquote>
<hr size=1>
<blockquote><p>
回复者：霏昀 回复日期：2003-01-05 12:46:55
<br>内容：#include "stdafx.h"<BR>#include "MyFrame.h"<BR>#define MLEFT 0;<BR>#define MRIGHT 1;<BR>#define MUP 2;<BR>#define MDOWN 3;<BR><BR>CMyFrame::CMyFrame()<BR>{<BR>&nbsp;&nbsp;&nbsp;&nbsp;Create(NULL,"Move");<BR>&nbsp;&nbsp;&nbsp;&nbsp;SetTimer(0,300,NULL);<BR>&nbsp;&nbsp;&nbsp;&nbsp;m_direction=MRIGHT;<BR>&nbsp;&nbsp;&nbsp;&nbsp;m_rect.top=0;<BR>&nbsp;&nbsp;&nbsp;&nbsp;m_rect.bottom=20;<BR>&nbsp;&nbsp;&nbsp;&nbsp;m_rect.left=0;<BR>&nbsp;&nbsp;&nbsp;&nbsp;m_rect.right=20;<BR>}<BR><BR>void CMyFrame::OnPaint()<BR>{<BR>&nbsp;&nbsp;&nbsp;&nbsp;CPaintDC dc(this);<BR>&nbsp;&nbsp;&nbsp;&nbsp;CDC *pDC=&amp;dc;<BR>&nbsp;&nbsp;&nbsp;&nbsp;CBrush newbrush((COLORREF) RGB(0,0,255));<BR>&nbsp;&nbsp;&nbsp;&nbsp;CBrush *oldbrush=pDC-&gt;SelectObject(&amp;newbrush);<BR>&nbsp;&nbsp;&nbsp;&nbsp;pDC-&gt;Rectangle(m_rect);<BR>&nbsp;&nbsp;&nbsp;&nbsp;pDC-&gt;SelectObject(oldbrush);<BR>}<BR><BR>void CMyFrame::OnTimer()<BR>{<BR>&nbsp;&nbsp;&nbsp;&nbsp;InvalidateRect(m_rect);<BR>&nbsp;&nbsp;&nbsp;&nbsp;switch(m_direction)<BR>&nbsp;&nbsp;&nbsp;&nbsp;{<BR>&nbsp;&nbsp;&nbsp;&nbsp;case MLEFT:m_rect.left-=20;break;//这里<BR>&nbsp;&nbsp;&nbsp;&nbsp;case MRIGHT:m_rect.left+=20;break;<BR>&nbsp;&nbsp;&nbsp;&nbsp;case MUP:m_rect.top-=20;break;<BR>&nbsp;&nbsp;&nbsp;&nbsp;case MDOWN:m_rect.top+=20;break;<BR>&nbsp;&nbsp;&nbsp;&nbsp;}<BR>&nbsp;&nbsp;&nbsp;&nbsp;m_rect.bottom=m_rect.top+20;<BR>&nbsp;&nbsp;&nbsp;&nbsp;m_rect.right=m_rect.left+20;<BR>&nbsp;&nbsp;&nbsp;&nbsp;InvalidateRect(m_rect);<BR>}<BR><BR>void CMyFrame::OnKeyDown(UINT nChar)<BR>{<BR>&nbsp;&nbsp;&nbsp;&nbsp;switch(nChar)<BR>&nbsp;&nbsp;&nbsp;&nbsp;{<BR>&nbsp;&nbsp;&nbsp;&nbsp;case VK_LEFT:m_direction=MLEFT;break;<BR>&nbsp;&nbsp;&nbsp;&nbsp;case VK_RIGHT:m_direction=MRIGHT;break;<BR>&nbsp;&nbsp;&nbsp;&nbsp;case VK_UP:m_direction=MUP;break;<BR>&nbsp;&nbsp;&nbsp;&nbsp;case VK_DOWN:m_direction=MDOWN;break;<BR>&nbsp;&nbsp;&nbsp;&nbsp;}<BR>}<BR><BR><BR>BEGIN_MESSAGE_MAP(CMyFrame, CFrameWnd)<BR>&nbsp;&nbsp;&nbsp;&nbsp;ON_WM_KEYDOWN()<BR>&nbsp;&nbsp;&nbsp;&nbsp;ON_WM_PAINT()<BR>&nbsp;&nbsp;&nbsp;&nbsp;ON_WM_TIMER()<BR>END_MESSAGE_MAP()<BR><BR><BR>OnTimer()里那个switch,改成0,1,2,3就可以？？<BR>d:\sakimove\myframe.cpp(34) : error C2143: syntax error : missing ';' before ':'<BR><BR>
<br>
<a href="javascript:history.go(-1)">返回上页</a><br><a href=http://www.copathway.com/cndevforum/>访问论坛</a></p></blockquote>
<hr size=1>
<blockquote><p>
<font color=red>答案被接受</font><br>回复者：tjhe 回复日期：2003-01-05 12:58:07
<br>内容：#define MLEFT 0;&nbsp;&nbsp; //不应该有分号<BR>#define MRIGHT 1;&nbsp;&nbsp;//不应该有分号<BR>#define MUP 2;&nbsp;&nbsp;&nbsp;&nbsp; //不应该有分号<BR>#define MDOWN 3;&nbsp;&nbsp; //不应该有分号
<br>
<a href="javascript:history.go(-1)">返回上页</a><br><a href=http://www.copathway.com/cndevforum/>访问论坛</a></p></blockquote>
<hr size=1>
<blockquote><p>
回复者：霏昀 回复日期：2003-01-05 13:05:32
<br>内容：太愚昧了……呵呵
<br>
<a href="javascript:history.go(-1)">返回上页</a><br><a href=http://www.copathway.com/cndevforum/>访问论坛</a></p></blockquote>
<hr size=1>
<blockquote><p>
回复者：oydy 回复日期：2003-01-05 13:05:48
<br>内容：#define MLEFT 0;<BR>#define MRIGHT 1;<BR>#define MUP 2;<BR>#define MDOWN 3;&nbsp;&nbsp;//&lt;---注意分号<BR><BR>switch(nChar)<BR>&nbsp;&nbsp;&nbsp;&nbsp;{<BR>&nbsp;&nbsp; case VK_LEFT;:m_direction=MLEFT;break; //&lt;--展开后多了分号<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;^^^^^^^^<BR>
<br>
<a href="javascript:history.go(-1)">返回上页</a><br><a href=http://www.copathway.com/cndevforum/>访问论坛</a></p></blockquote>