bigicon.cpp

visual c++ 实例编程

#include "stdafx.h"
#include "BigIcon.h"
/////////////////////////////////////////////////////////////////////////////
// CBigIcon

BEGIN_MESSAGE_MAP(CBigIcon, CButton)
	//{{AFX_MSG_MAP(CBigIcon)
	ON_WM_DRAWITEM()
	ON_WM_ERASEBKGND()
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CBigIcon message handlers

#define CY_SHADOW   4
#define CX_SHADOW   4

void CBigIcon::SizeToContent()
{
	// 获得系统图标大小
	int cxIcon = ::GetSystemMetrics(SM_CXICON);
	int cyIcon = ::GetSystemMetrics(SM_CYICON);

	// a big icon should be twice the size of an icon + shadows
	SetWindowPos(NULL, 0, 0, cxIcon*2 + CX_SHADOW + 4, cyIcon*2 + CY_SHADOW + 4,
		SWP_NOACTIVATE|SWP_NOMOVE|SWP_NOZORDER);
}

BOOL CBigIcon::OnEraseBkgnd(CDC*)
{
	return TRUE;    // we don't do any erasing...
}


void CBigIcon::DrawItem(LPDRAWITEMSTRUCT lpDrawItemStruct)
{
	CDC* pDC = CDC::FromHandle(lpDrawItemStruct->hDC);
	ASSERT(pDC != NULL);

	CRect rect;
	GetClientRect(rect);
	int cxClient = rect.Width();
	int cyClient = rect.Height();

	// load icon
	HICON hicon = AfxGetApp()->LoadIcon(IconID);
	if (hicon == NULL)
		return;

	// draw icon into off-screen bitmap
	int cxIcon = ::GetSystemMetrics(SM_CXICON);
	int cyIcon = ::GetSystemMetrics(SM_CYICON);

	CBitmap bitmap;
	if (!bitmap.CreateCompatibleBitmap(pDC, cxIcon, cyIcon))
		return;
	CDC dcMem;
	if (!dcMem.CreateCompatibleDC(pDC))
		return;
	CBitmap* pBitmapOld = dcMem.SelectObject(&bitmap);
	if (pBitmapOld == NULL)
		return;

	// blt the bits already on the window onto the off-screen bitmap
	dcMem.StretchBlt(0, 0, cxIcon, cyIcon, pDC,
		2, 2, cxClient-CX_SHADOW-4, cyClient-CY_SHADOW-4, SRCCOPY);

	// draw the icon on the background
	dcMem.DrawIcon(0, 0, hicon);

	// draw border around icon
	CPen pen;
	pen.CreateStockObject(BLACK_PEN);
	CPen* pPenOld = pDC->SelectObject(&pen);
	pDC->Rectangle(0, 0, cxClient-CX_SHADOW, cyClient-CY_SHADOW);
	if (pPenOld)
		pDC->SelectObject(pPenOld);

	// draw shadows around icon
	CBrush br;
	br.CreateStockObject(DKGRAY_BRUSH);
	rect.SetRect(cxClient-CX_SHADOW, CY_SHADOW, cxClient, cyClient);
	pDC->FillRect(rect, &br);
	rect.SetRect(CX_SHADOW, cyClient-CY_SHADOW, cxClient, cyClient);
	pDC->FillRect(rect, &br);

	// draw the icon contents
	pDC->StretchBlt(2, 2, cxClient-CX_SHADOW-4, cyClient-CY_SHADOW-4,
                &dcMem, 0, 0, cxIcon, cyIcon, SRCCOPY);
	//DrawIconEx(pDC->m_hDC,2,2,hicon,cxIcon*2,cyIcon*2,0,NULL,DI_NORMAL);
}