example13-2.htm

Visual C++面向对象程序设计教程（配套习题资源）

    <blockquote>
      <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">static 
      BOOL fBlocking, fValidBox ;</font></p>
      <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">static 
      POINT ptBeg, ptEnd, ptBoxBeg, ptBoxEnd ;</font></p>
      <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">HDC 
      hdc ;</font></p>
      <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">PAINTSTRUCT 
      ps ;</font></p>
      <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">switch 
      (iMsg)</font></p>
      <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">{</font></p>
      <blockquote>
        <blockquote>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">case 
          WM_LBUTTONDOWN :</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">ptBeg.x 
          = ptEnd.x = LOWORD (lParam) ;</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">ptBeg.y 
          = ptEnd.y = HIWORD (lParam) ;</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">DrawBoxOutline 
          (hwnd, ptBeg, ptEnd) ;</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">SetCursor 
          (LoadCursor (NULL, IDC_CROSS)) ;</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">fBlocking 
          = TRUE ;</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">return 
          0 ;</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0">　</p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">case 
          WM_MOUSEMOVE :</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">if 
          (fBlocking)</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">{</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">SetCursor 
          (LoadCursor (NULL, IDC_CROSS)) ;</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">DrawBoxOutline 
          (hwnd, ptBeg, ptEnd) ;</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">ptEnd.x 
          = LOWORD (lParam) ;</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">ptEnd.y 
          = HIWORD (lParam) ;</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">DrawBoxOutline 
          (hwnd, ptBeg, ptEnd) ;</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">}</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">return 
          0 ;</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0">　</p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">case 
          WM_LBUTTONUP :</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">if 
          (fBlocking)</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">{</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">DrawBoxOutline 
          (hwnd, ptBeg, ptEnd) ;</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">ptBoxBeg 
          = ptBeg ;</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">ptBoxEnd.x 
          = LOWORD (lParam) ;</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">ptBoxEnd.y 
          = HIWORD (lParam) ;</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">SetCursor 
          (LoadCursor (NULL, IDC_ARROW)) ;</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">fBlocking 
          = FALSE ;</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">fValidBox 
          = TRUE ;</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">InvalidateRect 
          (hwnd, NULL, TRUE) ;</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">}</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">return 
          0 ;</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0">　</p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">case 
          WM_CHAR :</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">if 
          (fBlocking &amp; wParam == '\x1B') // Escape</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">{</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">DrawBoxOutline 
          (hwnd, ptBeg, ptEnd) ;</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">SetCursor 
          (LoadCursor (NULL, IDC_ARROW)) ;</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">fBlocking 
          = FALSE ;</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">}</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">return 
          0 ;</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0">　</p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">case 
          WM_PAINT :</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">hdc 
          = BeginPaint (hwnd, &amp;ps) ;</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">if 
          (fValidBox)</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">{</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">SelectObject 
          (hdc, GetStockObject (BLACK_BRUSH)) ;</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">Rectangle 
          (hdc, ptBoxBeg.x, ptBoxBeg.y, ptBoxEnd.x, ptBoxEnd.y) ;</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">}</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">if 
          (fBlocking)</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">{</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">SetROP2 
          (hdc, R2_NOT) ;</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">SelectObject 
          (hdc, GetStockObject (NULL_BRUSH)) ;</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">Rectangle 
          (hdc, ptBeg.x, ptBeg.y, ptEnd.x, ptEnd.y) ;</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">}</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">EndPaint 
          (hwnd, &amp;ps) ;</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">return 
          0 ;</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0">　</p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">case 
          WM_DESTROY :</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">PostQuitMessage 
          (0) ;</font></p>
          <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">return 
          0 ;</font></p>
        </blockquote>
      </blockquote>
      <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">}</font></p>
      <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">return 
      DefWindowProc (hwnd, iMsg, wParam, lParam) ;</font></p>
    </blockquote>
    <p ALIGN="justify" style="line-height: 100%; margin-top: 0; margin-bottom: 0"><font size="2">}</font></p>
    <font SIZE="1">
    <p ALIGN="JUSTIFY">　</p>
    </blockquote>
    <p ALIGN="JUSTIFY">　</p>
  </font>
  <blockquote>
    <font SIZE="1">
    <p ALIGN="JUSTIFY">　</p>
    <p ALIGN="JUSTIFY">　</p>
    </blockquote>
  </blockquote>
</font>
<p>　</p>

</body>

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