picture.cpp

vc中处理jpeg文件以及vc中对现有jpeg图片建立数据库的文件。有较大参考价值

	memcpy(pData, pBuffer, nSize);
	GlobalUnlock(hGlobal);

	IStream* pStream = NULL;

	if(CreateStreamOnHGlobal(hGlobal, TRUE, &pStream) == S_OK)
		{
		HRESULT hr;
		if((hr = OleLoadPicture(pStream, nSize, FALSE, IID_IPicture, (LPVOID *)&m_IPicture)) == E_NOINTERFACE)
			{
			HWND hWnd = AfxGetApp()->GetMainWnd()->m_hWnd;
			MessageBoxEx(hWnd, "IPicture interface is not supported\t", ERROR_TITLE, MB_OK | MB_ICONSTOP, LANG_ENGLISH);
			return(FALSE);
			}
		else // S_OK
			{
			pStream->Release();
			pStream = NULL;
			bResult = TRUE;
			}
		}

	FreeResource(hGlobal); // 16Bit Windows Needs This (32Bit - Automatic Release)

	return(bResult);
}

//-----------------------------------------------------------------------------
// Does:   Draw The Loaded Picture Direct To The Client DC
// ~~~~
//
// Note:   Bigger OR Smaller Dimentions Than The Original Picture Size
// ~~~~    Will Draw The Picture Streached To Its New Given NEW Dimentions...
//
// InPut:  pDC - Given DC To Draw On
// ~~~~~   DrawRect - Dimentions Of The Picture To Draw (As a Rectangle)
//
// OutPut: TRUE If Succeeded...
// ~~~~~~
//-----------------------------------------------------------------------------
BOOL CPicture::Show(CDC *pDC, CRect DrawRect)
//=============================================================================
{
    if (pDC == NULL || m_IPicture == NULL) return FALSE;
    
    long Width  = 0;
    long Height = 0;
    m_IPicture->get_Width(&Width);
    m_IPicture->get_Height(&Height);

    HRESULT hrP = NULL;
    
    hrP = m_IPicture->Render(pDC->m_hDC,
                      DrawRect.left,                  // Left
                      DrawRect.top,                   // Top
                      DrawRect.right - DrawRect.left, // Right
                      DrawRect.bottom - DrawRect.top, // Bottom
                      0,
                      Height,
                      Width,
                      -Height,
                      &DrawRect);

    if (SUCCEEDED(hrP)) return(TRUE);

	HWND hWnd = AfxGetApp()->GetMainWnd()->m_hWnd;
	MessageBoxEx(hWnd, "Can not allocate enough memory\t", ERROR_TITLE, MB_OK | MB_ICONSTOP, LANG_ENGLISH);
    return(FALSE);
}

//-----------------------------------------------------------------------------
// Does:   Draw The Loaded Picture Direct To The Client DC
// ~~~~
//
// Note:   Bigger OR Smaller Dimentions Than The Original Picture Size
// ~~~~    Will Draw The Picture Streached To Its New Given Dimentions...
//
// InPut:  pDC - Given DC To Draw On
// ~~~~~   LeftTop - Opening Point To Start Drawing (Left,Top)
//         WidthHeight - Dimentions Of The Picture To Draw (Width,Height)
//         MagnifyX - Magnify Pixel Width, 0 = Default (No Magnify)
//         MagnifyY - Magnify Pixel Height, 0 = Default (No Magnify)
//
// OutPut: TRUE If Succeeded...
// ~~~~~~
//-----------------------------------------------------------------------------
BOOL CPicture::Show(CDC *pDC, CPoint LeftTop, CPoint WidthHeight, int MagnifyX, int MagnifyY)
//=============================================================================
{
    if (pDC == NULL || m_IPicture == NULL) return FALSE;
    
    long Width  = 0;
    long Height = 0;
    m_IPicture->get_Width(&Width);
    m_IPicture->get_Height(&Height);
	if(MagnifyX == NULL) MagnifyX = 0;
	if(MagnifyY == NULL) MagnifyY = 0;
	MagnifyX = int(MulDiv(Width, pDC->GetDeviceCaps(LOGPIXELSX), HIMETRIC_INCH) * MagnifyX);
	MagnifyY = int(MulDiv(Height,pDC->GetDeviceCaps(LOGPIXELSY), HIMETRIC_INCH) * MagnifyY);

	CRect DrawRect(LeftTop.x, LeftTop.y, MagnifyX, MagnifyY);

    HRESULT hrP = NULL;

    hrP = m_IPicture->Render(pDC->m_hDC,
                      LeftTop.x,               // Left
                      LeftTop.y,               // Top
                      WidthHeight.x +MagnifyX, // Width
                      WidthHeight.y +MagnifyY, // Height
                      0,
                      Height,
                      Width,
                      -Height,
                      &DrawRect);

    if(SUCCEEDED(hrP)) return(TRUE);

	HWND hWnd = AfxGetApp()->GetMainWnd()->m_hWnd;
	MessageBoxEx(hWnd, "Can not allocate enough memory\t", ERROR_TITLE, MB_OK | MB_ICONSTOP, LANG_ENGLISH);
    return(FALSE);
}

//-----------------------------------------------------------------------------
// Does:   Saves The Picture That Is Stored In The IPicture Object As a Bitmap
// ~~~~    (Converts From Any Known Picture Type To a Bitmap / Icon File)
//
// InPut:  sFilePathName - Path And FileName Target To Save
// ~~~~~
//
// OutPut: TRUE If Succeeded...
// ~~~~~~
//-----------------------------------------------------------------------------
BOOL CPicture::SaveAsBitmap(CString sFilePathName)
//=============================================================================
{
	BOOL bResult = FALSE;
	ILockBytes *Buffer = 0;
	IStorage   *pStorage = 0;
	IStream    *FileStream = 0;
	BYTE	   *BufferBytes;
	STATSTG		BytesStatistics;
	DWORD		OutData;
	long		OutStream;
	CFile		BitmapFile;	CFileException e;
	double		SkipFloat = 0;
	DWORD		ByteSkip = 0;
	_ULARGE_INTEGER RealData;

	CreateILockBytesOnHGlobal(NULL, TRUE, &Buffer); // Create ILockBytes Buffer

	HRESULT hr = ::StgCreateDocfileOnILockBytes(Buffer,
				 STGM_SHARE_EXCLUSIVE | STGM_CREATE | STGM_READWRITE, 0, &pStorage);

	hr = pStorage->CreateStream(L"PICTURE",
		 STGM_SHARE_EXCLUSIVE | STGM_CREATE | STGM_READWRITE, 0, 0, &FileStream);

	m_IPicture->SaveAsFile(FileStream, TRUE, &OutStream); // Copy Data Stream
	FileStream->Release();
	pStorage->Release();
	Buffer->Flush(); 

	// Get Statistics For Final Size Of Byte Array
	Buffer->Stat(&BytesStatistics, STATFLAG_NONAME);

	// Cut UnNeeded Data Coming From SaveAsFile() (Leave Only "Pure" Picture Data)
	SkipFloat = (double(OutStream) / 512); // Must Be In a 512 Blocks...
	if(SkipFloat > DWORD(SkipFloat)) ByteSkip = (DWORD)SkipFloat + 1;
	else ByteSkip = (DWORD)SkipFloat;
	ByteSkip = ByteSkip * 512; // Must Be In a 512 Blocks...
	
	// Find Difference Between The Two Values
	ByteSkip = (DWORD)(BytesStatistics.cbSize.QuadPart - ByteSkip);

	// Allocate Only The "Pure" Picture Data
	RealData.LowPart = 0;
	RealData.HighPart = 0;
	RealData.QuadPart = ByteSkip;
	BufferBytes = (BYTE*)malloc(OutStream);
	if(BufferBytes == NULL)
		{
		Buffer->Release();
		HWND hWnd = AfxGetApp()->GetMainWnd()->m_hWnd;
		MessageBoxEx(hWnd, "Can not allocate enough memory\t", ERROR_TITLE, MB_OK | MB_ICONSTOP, LANG_ENGLISH);
		}

	Buffer->ReadAt(RealData, BufferBytes, OutStream, &OutData);

	if(BitmapFile.Open(sFilePathName, CFile::typeBinary | CFile::modeCreate | CFile::modeWrite, &e))
		{
		BitmapFile.Write(BufferBytes, OutData);
		BitmapFile.Close();
		bResult = TRUE;
		}
	else // Write File Failed...
		{
		TCHAR szCause[255];
		e.GetErrorMessage(szCause, 255, NULL);
		HWND hWnd = AfxGetApp()->GetMainWnd()->m_hWnd;
		MessageBoxEx(hWnd, szCause, ERROR_TITLE, MB_OK | MB_ICONSTOP, LANG_ENGLISH);
		bResult = FALSE;
		}
	
	Buffer->Release();
	free(BufferBytes);

	return(bResult);
}

//-----------------------------------------------------------------------------
// Does:   Draw a Bitmap Resource To The Client DC (Using Bitblt())
// ~~~~    It Will Use The Bitmap Resource Original Size (Width And Height)
//         (.BMP .DIB)
//
// Note:   This Function Is Just Another Simple Way Of Displaying a Bitmap Resource,
// ~~~~    It Is Not Connected With The IPicture Interface And Can Be Used
//         As a StandAlone On Any Device Context (Directly)
//
// InPut:  BMPResource - Resource Name As Defined In The Resources
// ~~~~~   pDC - Given DC To Draw On
//         LeftTop - Opening Point To Start Drawing (Left,Top)
//
// OutPut: TRUE If Succeeded...
// ~~~~~~
//-----------------------------------------------------------------------------
BOOL CPicture::ShowBitmapResource(CDC *pDC, const int BMPResource, CPoint LeftTop)
//=============================================================================
{
   if (pDC == NULL) return(FALSE);

   CBitmap BMP;
   if(BMP.LoadBitmap(BMPResource))
		{
		// Get Bitmap Details
		BITMAP BMPInfo;
		BMP.GetBitmap(&BMPInfo);

		// Create An In-Memory DC Compatible With The Display DC We R Gonna Paint On
		CDC DCMemory;
		DCMemory.CreateCompatibleDC(pDC);

		// Select The Bitmap Into The In-Memory DC
		CBitmap* pOldBitmap = DCMemory.SelectObject(&BMP);

		// Copy Bits From The In-Memory DC Into The On-Screen DC
		pDC->BitBlt(LeftTop.x, LeftTop.y, BMPInfo.bmWidth, BMPInfo.bmHeight, &DCMemory, 0, 0, SRCCOPY);

		DCMemory.SelectObject(pOldBitmap); // (As Shown In MSDN Example...)
		}
	else 
		{
		TRACE0("ERROR: Can Not Find The Bitmap Resource\n");
		return(FALSE);
		}

	return(TRUE);
}

//-----------------------------------------------------------------------------
// Does:   Get The Original Picture Pixel Size (Ignor What Current DC Is Using)
// ~~~~    Pointer To a Device Context Is Needed For Pixel Calculation,
//
//         Also Updates The Class's Height And Width Properties,
//         (Coz Till Now We Had No Device Context To Work With...96 DPI Assumed)
//
// InPut:  The Client DC (Needed To Check The Size Of The Pixels)
// ~~~~~
//
// OutPut: TRUE If Succeeded...
// ~~~~~~
//-----------------------------------------------------------------------------
BOOL CPicture::UpdateSizeOnDC(CDC *pDC)
//=============================================================================
{
	if(pDC == NULL || m_IPicture == NULL) { m_Height = 0; m_Width = 0; return(FALSE); };

    m_IPicture->get_Height(&m_Height);
    m_IPicture->get_Width(&m_Width);

	// Get Current DPI - Dot Per Inch
    int CurrentDPI_X = pDC->GetDeviceCaps(LOGPIXELSX);
    int CurrentDPI_Y = pDC->GetDeviceCaps(LOGPIXELSY);

	// Use a "Standard" Print (When Printing)
    if(pDC->IsPrinting())
		{
		CurrentDPI_X = 96;
        CurrentDPI_Y = 96;
		}

    m_Height = MulDiv(m_Height, CurrentDPI_Y, HIMETRIC_INCH);
    m_Width  = MulDiv(m_Width,  CurrentDPI_X, HIMETRIC_INCH);

    return(TRUE);
}