保存位图？

clxye 2007-10-31 10:07:07

为什么我下面的代码保存的位图漆黑一片？



void CBitmapDlg::OnBtnBitmap() 

{

	// TODO: Add your control notification handler code here

	CClientDC dc( this );

	CDC dcMem;

	CRect rect;

	GetClientRect( &rect );



	//	位图文件头

	BITMAPFILEHEADER bmfh;



	//	位图信息头

	BITMAPINFO bmih;

	BYTE *pBytes;



	bmih.bmiHeader.biSize = sizeof( BITMAPINFOHEADER );

	bmih.bmiHeader.biWidth = rect.Width();

	bmih.bmiHeader.biHeight = rect.Height();

	bmih.bmiHeader.biPlanes = 1;

	bmih.bmiHeader.biBitCount = 16;

	bmih.bmiHeader.biCompression = BI_RGB;

	bmih.bmiHeader.biSizeImage = 0;

	bmih.bmiHeader.biXPelsPerMeter = 0;

	bmih.bmiHeader.biYPelsPerMeter = 0;

	bmih.bmiHeader.biClrUsed = 0;

	bmih.bmiHeader.biClrImportant = NULL;



	bmfh.bfType = 0x4d42;

	bmfh.bfSize = ( DWORD )( sizeof( BITMAPFILEHEADER ) + bmih.bmiHeader.biSize + bmih.bmiHeader.biClrUsed * sizeof( RGBQUAD ) + bmih.bmiHeader.biSizeImage); 

	bmfh.bfReserved1 = 0;

	bmfh.bfReserved2 = 0;

	bmfh.bfOffBits = ( DWORD )( sizeof( BITMAPFILEHEADER ) + bmih.bmiHeader.biSize + bmih.bmiHeader.biClrUsed * sizeof( RGBQUAD ) ); 



	dcMem.CreateCompatibleDC( &dc );

	dcMem.SetBkMode( TRANSPARENT );

	dcMem.MoveTo( 0, 0 );

	dcMem.LineTo( 100, 100 );



	CreateDIBSection( dcMem.m_hDC, &bmih, DIB_PAL_COLORS, ( void** )&pBytes, NULL, 0 );



	CFile file;

	if( file.Open( "c:\\Test.bmp", CFile::modeWrite | CFile::modeCreate ) )

    {

        file.Write( &bmfh, sizeof( BITMAPFILEHEADER ) );

        file.Write( &bmih, bmih.bmiHeader.biSize + bmih.bmiHeader.biClrUsed * sizeof( RGBQUAD ) + bmih.bmiHeader.biSizeImage );

        file.Write( pBytes, rect.Width() * rect.Height() * 16 / 8 );

        file.Close();

    }

	dcMem.DeleteDC();

}