bmptofiledlg.cpp

一个关于加密的例子

// BmptoFileDlg.cpp : implementation file
//

#include "stdafx.h"
#include "BmptoFile.h"
#include "BmptoFileDlg.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

/////////////////////////////////////////////////////////////////////////////
// CAboutDlg dialog used for App About

class CAboutDlg : public CDialog
{
public:
	CAboutDlg();

// Dialog Data
	//{{AFX_DATA(CAboutDlg)
	enum { IDD = IDD_ABOUTBOX };
	//}}AFX_DATA

	// ClassWizard generated virtual function overrides
	//{{AFX_VIRTUAL(CAboutDlg)
	protected:
	virtual void DoDataExchange(CDataExchange* pDX);    // DDX/DDV support
	//}}AFX_VIRTUAL

// Implementation
protected:
	//{{AFX_MSG(CAboutDlg)
	//}}AFX_MSG
	DECLARE_MESSAGE_MAP()
};

CAboutDlg::CAboutDlg() : CDialog(CAboutDlg::IDD)
{
	//{{AFX_DATA_INIT(CAboutDlg)
	//}}AFX_DATA_INIT
}

void CAboutDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CAboutDlg)
	//}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CAboutDlg, CDialog)
	//{{AFX_MSG_MAP(CAboutDlg)
		// No message handlers
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CBmptoFileDlg dialog

CBmptoFileDlg::CBmptoFileDlg(CWnd* pParent /*=NULL*/)
	: CDialog(CBmptoFileDlg::IDD, pParent)
{
	//{{AFX_DATA_INIT(CBmptoFileDlg)
		// NOTE: the ClassWizard will add member initialization here
	//}}AFX_DATA_INIT
	// Note that LoadIcon does not require a subsequent DestroyIcon in Win32
	m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
}

void CBmptoFileDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CBmptoFileDlg)
		// NOTE: the ClassWizard will add DDX and DDV calls here
	//}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CBmptoFileDlg, CDialog)
	//{{AFX_MSG_MAP(CBmptoFileDlg)
	ON_WM_SYSCOMMAND()
	ON_WM_PAINT()
	ON_WM_QUERYDRAGICON()
	ON_BN_CLICKED(IDC_BUTTON_CONVERT, OnButtonConvert)
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CBmptoFileDlg message handlers

BOOL CBmptoFileDlg::OnInitDialog()
{
	CDialog::OnInitDialog();

	// Add "About..." menu item to system menu.

	// IDM_ABOUTBOX must be in the system command range.
	ASSERT((IDM_ABOUTBOX & 0xFFF0) == IDM_ABOUTBOX);
	ASSERT(IDM_ABOUTBOX < 0xF000);

	CMenu* pSysMenu = GetSystemMenu(FALSE);
	if (pSysMenu != NULL)
	{
		CString strAboutMenu;
		strAboutMenu.LoadString(IDS_ABOUTBOX);
		if (!strAboutMenu.IsEmpty())
		{
			pSysMenu->AppendMenu(MF_SEPARATOR);
			pSysMenu->AppendMenu(MF_STRING, IDM_ABOUTBOX, strAboutMenu);
		}
	}

	// Set the icon for this dialog.  The framework does this automatically
	//  when the application's main window is not a dialog
	SetIcon(m_hIcon, TRUE);			// Set big icon
	SetIcon(m_hIcon, FALSE);		// Set small icon
	
	// TODO: Add extra initialization here
	
	return TRUE;  // return TRUE  unless you set the focus to a control
}

void CBmptoFileDlg::OnSysCommand(UINT nID, LPARAM lParam)
{
	if ((nID & 0xFFF0) == IDM_ABOUTBOX)
	{
		CAboutDlg dlgAbout;
		dlgAbout.DoModal();
	}
	else
	{
		CDialog::OnSysCommand(nID, lParam);
	}
}

// If you add a minimize button to your dialog, you will need the code below
//  to draw the icon.  For MFC applications using the document/view model,
//  this is automatically done for you by the framework.

void CBmptoFileDlg::OnPaint() 
{
	if (IsIconic())
	{
		CPaintDC dc(this); // device context for painting

		SendMessage(WM_ICONERASEBKGND, (WPARAM) dc.GetSafeHdc(), 0);

		// Center icon in client rectangle
		int cxIcon = GetSystemMetrics(SM_CXICON);
		int cyIcon = GetSystemMetrics(SM_CYICON);
		CRect rect;
		GetClientRect(&rect);
		int x = (rect.Width() - cxIcon + 1) / 2;
		int y = (rect.Height() - cyIcon + 1) / 2;

		// Draw the icon
		dc.DrawIcon(x, y, m_hIcon);
	}
	else
	{
		CDialog::OnPaint();
	}
}

// The system calls this to obtain the cursor to display while the user drags
//  the minimized window.
HCURSOR CBmptoFileDlg::OnQueryDragIcon()
{
	return (HCURSOR) m_hIcon;
}

void CBmptoFileDlg::OnButtonConvert() 
{
	CBitmap bitmap;
	if(!bitmap.LoadBitmap(IDB_BITMAP_CONVERT))
		AfxMessageBox("Load bitmap error!");

	char* szfile;
	szfile = "bmptofile.bmp";
	HANDLE hdib = DDBToDIB(bitmap, BI_RGB, NULL);
	CFile file;
	file.Open(szfile, CFile::modeCreate | CFile::modeWrite);
	SaveDIB( hdib, file);
}


//////////////////////////////////////////////////////////////////////
//convert ddb to dib 
//CBitmap			--	your bitmap
//dwCompression		--	see BITMAPINFOHEADER
//CPalette			--	the palette of the bitmap
//return			--	handle of a dib
HANDLE CBmptoFileDlg::DDBToDIB(CBitmap &bitmap, DWORD dwCompression, CPalette* pPal)
{
	BITMAP			bm;
	BITMAPINFOHEADER	bi;
	LPBITMAPINFOHEADER 	lpbi;
	DWORD			dwlen;
	HANDLE			hdib;
	HANDLE			handle;
	HDC 			hdc;
	HPALETTE		hpal;


	ASSERT( bitmap.GetSafeHandle() );

	// the function has no arg for bitfields
	if( dwCompression == BI_BITFIELDS )
		return NULL;

	// if a palette has not been supplied use defaul palette
	hpal = (HPALETTE) pPal->GetSafeHandle();
	if (hpal==NULL)
		hpal = (HPALETTE) GetStockObject(DEFAULT_PALETTE);

	// get bitmap information
	bitmap.GetObject(sizeof(bm),(LPSTR)&bm);

	// initialize the bitmapinfoheader
	bi.biSize 			= sizeof(BITMAPINFOHEADER);
	bi.biWidth			= bm.bmWidth;
	bi.biHeight			= bm.bmHeight;
	bi.biPlanes 		= 1;
	bi.biBitCount		= bm.bmPlanes * bm.bmBitsPixel;
	bi.biCompression	= dwCompression;
	bi.biSizeImage 		= 0;
	bi.biXPelsPerMeter  = 0;
	bi.biYPelsPerMeter	= 0;
	bi.biClrUsed 		= 0;
	bi.biClrImportant 	= 0;

	// compute the size of the infoheader and the color table
	int ncolors = (1 << bi.biBitCount ); 
	if( ncolors> 256 ) 
		ncolors = 0;
	dwlen  = bi.biSize + ncolors * sizeof(RGBQUAD);

	// we need a device context to get the dib from
	hdc = ::GetDC(NULL);
	hpal = SelectPalette(hdc,hpal,FALSE);
	RealizePalette(hdc);

	// allocate enough memory to hold bitmapinfoheader and color table
	hdib = GlobalAlloc(GMEM_FIXED,dwlen);

	if (!hdib){
		SelectPalette(hdc,hpal,FALSE);
		::ReleaseDC(NULL,hdc);
		return NULL;
	}

	lpbi = (LPBITMAPINFOHEADER)hdib;

	*lpbi = bi;

	// call getdibits with a NULL lpbits param, so the device driver 
	// will calculate the bisizeimage field 
	GetDIBits(hdc, (HBITMAP)bitmap.GetSafeHandle(), 0L, (DWORD)bi.biHeight,
			(LPBYTE)NULL, (LPBITMAPINFO)lpbi, (DWORD)DIB_RGB_COLORS);

	bi = *lpbi;

	// if the driver did not fill in the bisizeimage field, then compute it
	// each scan line of the image is aligned on a dword (32bit) boundary
	if (bi.biSizeImage == 0){
		bi.biSizeImage = ((((bi.biWidth * bi.biBitCount) + 31) & ~31) / 8) 
						* bi.biHeight;

		// if a compression scheme is used the result may infact be larger
		// increase the size to account for this.
		if (dwCompression != BI_RGB)
			bi.biSizeImage = (bi.biSizeImage * 3) / 2;
	}

	// realloc the buffer so that it can hold all the bits
	dwlen += bi.biSizeImage;
	if (handle = GlobalReAlloc(hdib, dwlen, GMEM_MOVEABLE))
		hdib = handle;
	else{
		GlobalFree(hdib);

		// reselect the original palette
		SelectPalette(hdc,hpal,FALSE);
		::ReleaseDC(NULL,hdc);
		return NULL;
	}

	// get the bitmap bits
	lpbi = (LPBITMAPINFOHEADER)hdib;

	// finally get the dib
	BOOL bgotbits = GetDIBits( hdc, (HBITMAP)bitmap.GetSafeHandle(),
				0L,				// start scan line
				(DWORD)bi.biHeight,		// # of scan lines
				(LPBYTE)lpbi 			// address for bitmap bits
				+ (bi.biSize + ncolors * sizeof(RGBQUAD)),
				(LPBITMAPINFO)lpbi,		// address of bitmapinfo
				(DWORD)DIB_RGB_COLORS);		// use rgb for color table

	if( !bgotbits )
	{
		GlobalFree(hdib);
		
		SelectPalette(hdc,hpal,FALSE);
		::ReleaseDC(NULL,hdc);
		return NULL;
	}

	SelectPalette(hdc,hpal,FALSE);
	::ReleaseDC(NULL,hdc);
	return hdib;

}



BOOL CBmptoFileDlg::SaveDIB(HANDLE hDib, CFile &file)
{
	BITMAPFILEHEADER bmfHdr; // Header for Bitmap file
	LPBITMAPINFOHEADER lpBI;   // Pointer to DIB info structure
	DWORD dwDIBSize;

	if (hDib == NULL)
		return FALSE;

	/*
	 * Get a pointer to the DIB memory, the first of which contains
	 * a BITMAPINFO structure
	 */
	lpBI = (LPBITMAPINFOHEADER) ::GlobalLock((HGLOBAL) hDib);
	if (lpBI == NULL)
		return FALSE;
	if (!IS_WIN30_DIB(lpBI))
	{
		::GlobalUnlock((HGLOBAL) hDib);
		return FALSE;       // It's an other-style DIB (save not supported)
	}
	/*
	 * Fill in the fields of the file header
	 */

	/* Fill in file type (first 2 bytes must be "BM" for a bitmap) */
	bmfHdr.bfType = DIB_HEADER_MARKER;  // "BM"

	// Calculating the size of the DIB is a bit tricky (if we want to
	// do it right).  The easiest way to do this is to call GlobalSize()
	// on our global handle, but since the size of our global memory may have
	// been padded a few bytes, we may end up writing out a few too
	// many bytes to the file (which may cause problems with some apps).
	//
	// So, instead let's calculate the size manually (if we can)
	//
	// First, find size of header plus size of color table.  Since the
	// first DWORD in both BITMAPINFOHEADER and BITMAPCOREHEADER conains
	// the size of the structure, let's use this.

	dwDIBSize = *(LPDWORD)lpBI + PaletteSize((LPSTR)lpBI);  // Partial Calculation

	// Now calculate the size of the image

	if ((lpBI->biCompression == BI_RLE8) || (lpBI->biCompression == BI_RLE4))
	{
		// It's an RLE bitmap, we can't calculate size, so trust the
		// biSizeImage field

		dwDIBSize += lpBI->biSizeImage;
	}
	else
	{
		DWORD dwBmBitsSize;  // Size of Bitmap Bits only

		// It's not RLE, so size is Width (DWORD aligned) * Height

		dwBmBitsSize = WIDTHBYTES((lpBI->biWidth)*((DWORD)lpBI->biBitCount)) * lpBI->biHeight;

		dwDIBSize += dwBmBitsSize;

		// Now, since we have calculated the correct size, why don't we
		// fill in the biSizeImage field (this will fix any .BMP files which
		// have this field incorrect).

		lpBI->biSizeImage = dwBmBitsSize;
	}


	// Calculate the file size by adding the DIB size to sizeof(BITMAPFILEHEADER)

	bmfHdr.bfSize = dwDIBSize + sizeof(BITMAPFILEHEADER);
	bmfHdr.bfReserved1 = 0;
	bmfHdr.bfReserved2 = 0;

	/*
	 * Now, calculate the offset the actual bitmap bits will be in
	 * the file -- It's the Bitmap file header plus the DIB header,
	 * plus the size of the color table.
	 */
	bmfHdr.bfOffBits = (DWORD)sizeof(BITMAPFILEHEADER) + lpBI->biSize
											  + PaletteSize((LPSTR)lpBI);
	TRY
	{
		// Write the file header
		file.Write((LPSTR)&bmfHdr, sizeof(BITMAPFILEHEADER));
		//
		// Write the DIB header and the bits
		//
		file.WriteHuge(lpBI, dwDIBSize);
	}
	CATCH (CFileException, e)
	{
		::GlobalUnlock((HGLOBAL) hDib);
		THROW_LAST();
	}
	END_CATCH

	::GlobalUnlock((HGLOBAL) hDib);
	return TRUE;
}

DWORD CBmptoFileDlg::PaletteSize(LPSTR lpBI)
{
   /* calculate the size required by the palette */
   if (IS_WIN30_DIB (lpBI))
	  return (WORD)(DIBNumColors(lpBI) * sizeof(RGBQUAD));
   else
	  return (WORD)(DIBNumColors(lpBI) * sizeof(RGBTRIPLE));
}

WORD CBmptoFileDlg::DIBNumColors(LPSTR lpbi)
{
	WORD wBitCount;  // DIB bit count

	/*  If this is a Windows-style DIB, the number of colors in the
	 *  color table can be less than the number of bits per pixel
	 *  allows for (i.e. lpbi->biClrUsed can be set to some value).
	 *  If this is the case, return the appropriate value.
	 */

	if (IS_WIN30_DIB(lpbi))
	{
		DWORD dwClrUsed;

		dwClrUsed = ((LPBITMAPINFOHEADER)lpbi)->biClrUsed;
		if (dwClrUsed != 0)
			return (WORD)dwClrUsed;
	}

	/*  Calculate the number of colors in the color table based on
	 *  the number of bits per pixel for the DIB.
	 */
	if (IS_WIN30_DIB(lpbi))
		wBitCount = ((LPBITMAPINFOHEADER)lpbi)->biBitCount;
	else
		wBitCount = ((LPBITMAPCOREHEADER)lpbi)->bcBitCount;

	/* return number of colors based on bits per pixel */
	switch (wBitCount)
	{
		case 1:
			return 2;

		case 4:
			return 16;

		case 8:
			return 256;

		default:
			return 0;
	}
}