图片显示

开发平台：
Visual C++

DEMOVIEW.CPP：源码内容
							// demoView.cpp : implementation of the CDemoView class
//
#include "stdafx.h"
#include "cimage.h"
#include "demo.h"
#include "demoDoc.h"
#include "demoView.h"
#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif
/////////////////////////////////////////////////////////////////////////////
// CDemoView
IMPLEMENT_DYNCREATE(CDemoView, CScrollView)
BEGIN_MESSAGE_MAP(CDemoView, CScrollView)
	//{{AFX_MSG_MAP(CDemoView)
		// NOTE - the ClassWizard will add and remove mapping macros here.
		//    DO NOT EDIT what you see in these blocks of generated code!
	//}}AFX_MSG_MAP
	// Standard printing commands
	ON_COMMAND(ID_FILE_PRINT, CScrollView::OnFilePrint)
	ON_COMMAND(ID_FILE_PRINT_DIRECT, CScrollView::OnFilePrint)
	ON_COMMAND(ID_FILE_PRINT_PREVIEW, CScrollView::OnFilePrintPreview)
END_MESSAGE_MAP()
/////////////////////////////////////////////////////////////////////////////
// CDemoView construction/destruction
CDemoView::CDemoView()
{
	SetScrollSizes(MM_TEXT, CSize(0, 0));
}
CDemoView::~CDemoView()
{
}
BOOL CDemoView::PreCreateWindow(CREATESTRUCT& cs)
{
	// TODO: Modify the Window class or styles here by modifying
	//  the CREATESTRUCT cs
	return CScrollView::PreCreateWindow(cs);
}
/////////////////////////////////////////////////////////////////////////////
// CDemoView drawing
void CDemoView::OnDraw(CDC* pDC)
{
	CDemoDoc* pDoc = GetDocument();
	ASSERT_VALID(pDoc);
	CPoint pos(GetScrollPosition());
	CRect rect;
	GetClientRect(&rect);
	int width = rect.right - rect.left;
	int height = rect.bottom - rect.top;
	if (pDoc->GetImage())
	{
		int x = -pos.x;
		int y = -pos.y;
		if (width >= pDoc->GetImage()->GetWidth())
			x = (width - pDoc->GetImage()->GetWidth())/2;
		if (height >= pDoc->GetImage()->GetHeight())
			y = (height - pDoc->GetImage()->GetHeight())/2;
		CDC *dc = GetDC();
		CPalette *hOldPal = 0;
		if (pDoc->GetImage()->GetPalette())
		{
			hOldPal = dc->SelectPalette(pDoc->GetImage()->GetPalette(), TRUE);
			dc->RealizePalette();
		}
		if (pDoc->GetStretchMode())
		{
			SetScrollSizes(MM_TEXT,
				CSize(0,0));
			pDoc->GetImage()->Stretch(dc, 0, 0, width, height);
		}
		else
		{
			SetScrollSizes(MM_TEXT,
				CSize(pDoc->GetImage()->GetWidth(), pDoc->GetImage()->GetHeight()));
			pDoc->GetImage()->Draw(dc, x, y);
		}
//		dc->SelectPalette(hOldPal, TRUE);
		ReleaseDC(dc);
	}
}
/////////////////////////////////////////////////////////////////////////////
// CDemoView printing
BOOL CDemoView::OnPreparePrinting(CPrintInfo* pInfo)
{
	// default preparation
	return DoPreparePrinting(pInfo);
}
void CDemoView::OnBeginPrinting(CDC* /*pDC*/, CPrintInfo* /*pInfo*/)
{
	// TODO: add extra initialization before printing
}
void CDemoView::OnEndPrinting(CDC* /*pDC*/, CPrintInfo* /*pInfo*/)
{
	// TODO: add cleanup after printing
}
/////////////////////////////////////////////////////////////////////////////
// CDemoView diagnostics
#ifdef _DEBUG
void CDemoView::AssertValid() const
{
	CScrollView::AssertValid();
}
void CDemoView::Dump(CDumpContext& dc) const
{
	CScrollView::Dump(dc);
}
CDemoDoc* CDemoView::GetDocument() // non-debug version is inline
{
	ASSERT(m_pDocument->IsKindOf(RUNTIME_CLASS(CDemoDoc)));
	return (CDemoDoc*)m_pDocument;
}
#endif //_DEBUG
/////////////////////////////////////////////////////////////////////////////
// CDemoView message handlers
void CDemoView::OnInitialUpdate() 
{
	CScrollView::OnInitialUpdate();
	
	if (GetDocument()->GetImage())
		SetScrollSizes(MM_TEXT,
		  CSize(GetDocument()->GetImage()->GetWidth(), GetDocument()->GetImage()->GetHeight()));
}

						