jpeglibtestdlg.cpp

windows ce开发技巧与实例光盘代码

// JpegLibTestDlg.cpp : implementation file
//

#include "stdafx.h"
#include "JpegLibTest.h"
#include "JpegLibTestDlg.h"

#include "STScreenBuffer.h"
#include "ByteArray.h"
extern "C" {
	#include "../JpegLib/jpeglib.h"
}

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

/////////////////////////////////////////////////////////////////////////////
// CJpegLibTestDlg dialog

CJpegLibTestDlg::CJpegLibTestDlg(CWnd* pParent /*=NULL*/)
	: CDialog(CJpegLibTestDlg::IDD, pParent), m_hBitmap(0)
{
	//{{AFX_DATA_INIT(CJpegLibTestDlg)
		// 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 CJpegLibTestDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CJpegLibTestDlg)
		// NOTE: the ClassWizard will add DDX and DDV calls here
	//}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CJpegLibTestDlg, CDialog)
	//{{AFX_MSG_MAP(CJpegLibTestDlg)
	ON_WM_PAINT()
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CJpegLibTestDlg message handlers

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

	// 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
	
	CenterWindow(GetDesktopWindow());	// center to the hpc screen
	m_hBitmap = LoadImage(_T("\\My Documents\\t.jpg"));
	if (! m_hBitmap) {
		return FALSE;	
	}
	return TRUE;  // return TRUE  unless you set the focus to a control
}


HBITMAP CJpegLibTestDlg::LoadImage(const CString &strFileName)
{
	FILE * pFile;		
	JSAMPARRAY pBuffer;	
	int nRowSize;	
	ByteArray imageData(320*240*3);
	struct jpeg_error_mgr jerr;
	struct jpeg_decompress_struct cinfo;

	
	if ((pFile = _tfopen(strFileName, _T("rb"))) == NULL) {
		CString strError;
		strError.Format(_T("Can't open file '%s'"), strFileName);
		AfxMessageBox(strError);
		return 0;
	}
	
	cinfo.err = jpeg_std_error(&jerr);
	jpeg_create_decompress(&cinfo);
	jpeg_stdio_src(&cinfo, pFile);
	jpeg_read_header(&cinfo, TRUE);
	jpeg_start_decompress(&cinfo);
	nRowSize = cinfo.output_width * cinfo.output_components;
	pBuffer = (*cinfo.mem->alloc_sarray)
		((j_common_ptr) &cinfo, JPOOL_IMAGE, nRowSize, 1);
	while (cinfo.output_scanline < cinfo.output_height) {
		jpeg_read_scanlines(&cinfo, pBuffer, 1);
		imageData.Append(pBuffer[0], nRowSize);
	}

	HBITMAP hBitmap = CSTScreenBuffer::CreateBitmapByRGBArray(imageData.GetData(), cinfo.output_width, cinfo.output_height);

	jpeg_finish_decompress(&cinfo);
	jpeg_destroy_decompress(&cinfo);
	fclose(pFile);

	return hBitmap;
}

void CJpegLibTestDlg::OnPaint() 
{
	CPaintDC dc(this); 
	if (m_hBitmap) {
	    CDC memDc;
		VERIFY(memDc.CreateCompatibleDC(&dc));
	    HBITMAP hOldBitmap = (HBITMAP)::SelectObject(memDc.GetSafeHdc(), m_hBitmap);
		VERIFY(dc.BitBlt(0, 0, 240, 320, &memDc, 0, 0, SRCCOPY));
	    ::SelectObject(memDc.GetSafeHdc(), hOldBitmap);
		VERIFY( memDc.DeleteDC() );
	}
}