C / C++ / MFC

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      GetClientRect(hDlg, &rc); // Get the rectangle dimensions of the Dialog Box<br />
      <br />
      hdc = GetDC(hDlg);  // Get a handle to the Drawing Context of the Dialog Box<br />
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      blankDC = GetDC(NULL);<br />
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      rc.bottom -= (GetSystemMetrics(SM_CYHSCROLL)+GetSystemMetrics(SM_CYEDGE));<br />
      <br />
      hSavedXYContext = CreateCompatibleDC(hdc);  // Create a drawing context that is <br />
                                                  // compatiable to                                                  the drawing context on the screen     <br />
      hSavedXYBitmap = CreateCompatibleBitmap(hdc, rc.right-rc.left,rc.bottom-rc.top);  <br />
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      hUnSelectedBitmap= CreateCompatibleBitmap(hdc,rc.right-rc.left,rc.bottom-rc.top);<br />
      <br />
      SelectObject(hSavedXYContext, hSavedXYBitmap);  <br />
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      BitBlt(hSavedXYContext,0,0,rc.right-rc.left, rc.bottom-rc.top,hdc,0,0,SRCCOPY);<br />
      <br />
      // As far as I can tell above code does exactly what it should.  It grabs a<br />
      // handle to the drawing context, along with the rectangular coordinates of the       <br />
      // drawing context.  Then after creating a compatible bitmap, and selecting it<br />
      // into the saved drawing context, before blting it in.  <br />
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<br />
      // Now we have the DC saved to hSavedContext, so we need to take it and create a <br />
      // bitmap file that we can open in Paint.  <br />
      // This involves creating a bmp structure then writing it to a file.<br />
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      GetObject(hSavedXYBitmap,sizeof(BITMAP),(LPSTR)(&bmp));<br />
      <br />
      cClrBits = (WORD)(bmp.bmPlanes*bmp.bmBitsPixel);<br />
      <br />
      cClrBits = 32;<br />
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      pbmi = (PBITMAPINFO) LocalAlloc(LPTR,sizeof(BITMAPINFOHEADER));<br />
      <br />
      // Initialize the fields in the BITMAPINFO structure.<br />
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      pbmi->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);<br />
      pbmi->bmiHeader.biWidth = bmp.bmWidth;<br />
      pbmi->bmiHeader.biHeight = bmp.bmHeight;<br />
      pbmi->bmiHeader.biPlanes = bmp.bmPlanes;<br />
      pbmi->bmiHeader.biBitCount = bmp.bmBitsPixel;<br />
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      pbmi->bmiHeader.biCompression = BI_RGB;<br />
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      pbmi->bmiHeader.biSizeImage = (pbmi->bmiHeader.biWidth + 15)/16 <br />
                                      * pbmi->bmiHeader.biHeight * cClrBits;<br />
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      pbmi->bmiHeader.biClrImportant = 0;<br />
          <br />
      // Make sure to fill in the rest of the BITMAP info in the header.<br />
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      pBitmapInfoHeader = (PBITMAPINFOHEADER)pbmi;<br />
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      lpBits = (LPBYTE) GlobalAlloc(GMEM_FIXED,pBitmapInfoHeader->biSizeImage);<br />
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      GetDIBits(hdc,hUnSelectedBitmap,0,(WORD) pbmi->bmiHeader.biHeight,<br />
                lpBits,pbmi,DIB_RGB_COLORS);<br />
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