myview.cpp

这是树上的代码

// MyView.cpp : implementation of the CMyView class
//

#include "stdafx.h"
#include "My.h"

#include "MyDoc.h"
#include "MyView.h"

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

/////////////////////////////////////////////////////////////////////////////
// CMyView

IMPLEMENT_DYNCREATE(CMyView, CView)

BEGIN_MESSAGE_MAP(CMyView, CView)
	//{{AFX_MSG_MAP(CMyView)
	ON_WM_LBUTTONDOWN()
	//}}AFX_MSG_MAP
	// Standard printing commands
	ON_COMMAND(ID_FILE_PRINT, CView::OnFilePrint)
	ON_COMMAND(ID_FILE_PRINT_DIRECT, CView::OnFilePrint)
	ON_COMMAND(ID_FILE_PRINT_PREVIEW, CView::OnFilePrintPreview)
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CMyView construction/destruction

CMyView::CMyView()
{
	// TODO: add construction code here
	// 载入位图资源,读位图信息
	m_Bitmap.LoadBitmap(IDB_BITMAP1);
	BITMAP BM;
	m_Bitmap.GetBitmap(&BM);
	m_nWidth = BM.bmWidth;
	m_nHeight = BM.bmHeight;

}

CMyView::~CMyView()
{
}

BOOL CMyView::PreCreateWindow(CREATESTRUCT& cs)
{
	// TODO: Modify the Window class or styles here by modifying
	//  the CREATESTRUCT cs

	return CView::PreCreateWindow(cs);
}

/////////////////////////////////////////////////////////////////////////////
// CMyView drawing

// 响应绘制窗口客户区消息
void CMyView::OnDraw(CDC* pDC)
{
	CMyDoc* pDoc = GetDocument();
	ASSERT_VALID(pDoc);
	// TODO: add draw code for native data here
	// 显示位图
	pDoc->m_pView=this;
	CDC MemDC;
	MemDC.CreateCompatibleDC(NULL);
	MemDC.SelectObject(&m_Bitmap);
	pDC->BitBlt(0,0,m_nWidth,m_nHeight,&MemDC,0,0,SRCCOPY);
	pDC->TextOut(10,180,"单击鼠标左键保存客户区");
}

/////////////////////////////////////////////////////////////////////////////
// CMyView printing

BOOL CMyView::OnPreparePrinting(CPrintInfo* pInfo)
{
	// default preparation
	return DoPreparePrinting(pInfo);
}

void CMyView::OnBeginPrinting(CDC* /*pDC*/, CPrintInfo* /*pInfo*/)
{
	// TODO: add extra initialization before printing
}

void CMyView::OnEndPrinting(CDC* /*pDC*/, CPrintInfo* /*pInfo*/)
{
	// TODO: add cleanup after printing
}

/////////////////////////////////////////////////////////////////////////////
// CMyView diagnostics

#ifdef _DEBUG
void CMyView::AssertValid() const
{
	CView::AssertValid();
}

void CMyView::Dump(CDumpContext& dc) const
{
	CView::Dump(dc);
}

CMyDoc* CMyView::GetDocument() // non-debug version is inline
{
	ASSERT(m_pDocument->IsKindOf(RUNTIME_CLASS(CMyDoc)));
	return (CMyDoc*)m_pDocument;
}
#endif //_DEBUG

/////////////////////////////////////////////////////////////////////////////
// CMyView message handlers
BOOL CMyView::WriteWindowToDIB( LPTSTR szFile, CWnd *pWnd )
{
	CBitmap 	bitmap;
	CWindowDC	dc(pWnd);
	CDC 		memDC;
	CRect		rect;

	memDC.CreateCompatibleDC(&dc);//创建内存设备环境对象
	pWnd->GetWindowRect(rect);//取得窗口区域大小
	bitmap.CreateCompatibleBitmap(&dc, rect.Width(),rect.Height() );
	//创建一个位图对对象，并将窗口图像暂存其中
	CBitmap* pOldBitmap = memDC.SelectObject(&bitmap);
	memDC.BitBlt(0, 0, rect.Width(),rect.Height(), &dc, 0, 0, SRCCOPY);
	// 如果设备支持调色板，创建调色板
	CPalette pal;
	if( dc.GetDeviceCaps(RASTERCAPS) & RC_PALETTE )
	{
		UINT nSize = sizeof(LOGPALETTE) + (sizeof(PALETTEENTRY) * 256);
		LOGPALETTE *pLP = (LOGPALETTE *) new BYTE[nSize];
		pLP->palVersion = 0x300;

		pLP->palNumEntries =
			GetSystemPaletteEntries( dc, 0, 255, pLP->palPalEntry );
		// 创建调色板
		pal.CreatePalette( pLP );
		delete[] pLP;
	}
	memDC.SelectObject(pOldBitmap);
	HANDLE hDIB = DDBToDIB( bitmap, BI_RGB, &pal );// 转换Bitmap 到DIB
	if( hDIB == NULL )
		return FALSE;
	WriteDIB( szFile, hDIB );//将DIB保存到文件
	GlobalFree( hDIB );//释放DIB对象所占空间
	return TRUE;
}
// DDBToDIB		- Creates a DIB from a DDB
// bitmap		- Device dependent bitmap
// dwCompression	- Type of compression - see BITMAPINFOHEADER
// pPal			- Logical palette
HANDLE CMyView::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() );
	if( dwCompression == BI_BITFIELDS )//位图是否压缩
		return NULL;
	hPal = (HPALETTE) pPal->GetSafeHandle();//选择调色板
	if (hPal==NULL)
		hPal = (HPALETTE) GetStockObject(DEFAULT_PALETTE);
	bitmap.GetObject(sizeof(bm),(LPSTR)&bm);//获取位图的属性信息
	// 初始化位图文件头结构
	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;
	// 计算位图信息结构和位图颜色表的大小
	int nColors = (1 << bi.biBitCount);
	if( nColors > 256 )
		nColors = 0;
	dwLen  = bi.biSize + nColors * sizeof(RGBQUAD);
	// 为DIB创建一个设备环境
	hDC = ::GetDC(NULL);
	hPal = SelectPalette(hDC,hPal,FALSE);
	RealizePalette(hDC);
	// 为位图信息头结构和颜色表分配内存
	hDIB = GlobalAlloc(GMEM_FIXED,dwLen);
	if (!hDIB){
		SelectPalette(hDC,hPal,FALSE);
		::ReleaseDC(NULL,hDC);
		return NULL;
	}
	lpbi = (LPBITMAPINFOHEADER)hDIB;
	*lpbi = bi;
	// 计算位图字节数
	GetDIBits(hDC, (HBITMAP)bitmap.GetSafeHandle(), 0L, (DWORD)bi.biHeight,
			(LPBYTE)NULL, (LPBITMAPINFO)lpbi, (DWORD)DIB_RGB_COLORS);
	bi = *lpbi;
	// 如果biSizeImage为0，重新计算
	if (bi.biSizeImage == 0){
		bi.biSizeImage = ((((bi.biWidth * bi.biBitCount) + 31) & ~31) / 8)
						* bi.biHeight;
		if (dwCompression != BI_RGB)//如果为图压缩
			bi.biSizeImage = (bi.biSizeImage * 3) / 2;
	}
	// 给最终的位图尺寸分配内存块，包括位图信息头结构和颜色表与位图字节数
	dwLen += bi.biSizeImage;
	if (handle = GlobalReAlloc(hDIB, dwLen, GMEM_MOVEABLE))
		hDIB = handle;
	else{
		GlobalFree(hDIB);

		// 重新选择原始调色板
		SelectPalette(hDC,hPal,FALSE);
		::ReleaseDC(NULL,hDC);
		return NULL;
	}
	lpbi = (LPBITMAPINFOHEADER)hDIB;
	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;
}
// WriteDIB - Writes a DIB to file
// Returns - TRUE on success
// szFile - Name of file to write to
// hDIB - Handle of the DIB
BOOL CMyView::WriteDIB( LPTSTR szFile, HANDLE hDIB)
{
	BITMAPFILEHEADER hdr;
	LPBITMAPINFOHEADER lpbi;
	if (!hDIB)
		return FALSE;
	CFile file;
	if( !file.Open( szFile, CFile::modeWrite|CFile::modeCreate) )
		return FALSE;
	lpbi = (LPBITMAPINFOHEADER)hDIB;
	int nColors = 1 << lpbi->biBitCount;
	// 填充为图文件头结构
	hdr.bfType = ((WORD) ('M' << 8) | 'B'); // "BM"标志
	hdr.bfSize=::GlobalSize (hDIB) + sizeof( hdr );
	hdr.bfReserved1=0;
	hdr.bfReserved2=0; 
	hdr.bfOffBits=(DWORD) (sizeof( hdr ) + lpbi->biSize +nColors * sizeof(RGBQUAD));
	file.Write( &hdr, sizeof(hdr) );
	// DIB头结构和位图像素数据存盘
	file.Write( lpbi, GlobalSize(hDIB) );
	return TRUE;
}

void CMyView::OnLButtonDown(UINT nFlags, CPoint point) 
{
	// TODO: Add your message handler code here and/or call default
	WriteWindowToDIB( "My.bmp", this );
	CView::OnLButtonDown(nFlags, point);
}