C / C++ / MFC

m_psp.dwFlags |= PSP_USETITLE;
m_psp.pszTitle = _T("Hi!");

CString strTitle(_T("Hi!"));

m_psp.dwFlags |= PSP_USETITLE;
m_psp.pszTitle = strTitle;

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<br />
HPALETTE		hPal;<br />
	CDC*            pDC;<br />
<br />
	ASSERT( bitmap.GetSafeHandle() );<br />
<br />
	// The function has no arg for bitfields<br />
	if( dwCompression == BI_BITFIELDS )<br />
		return NULL;<br />
<br />
	// If a palette has not been supplied use defaul palette<br />
	hPal = (HPALETTE) pPal->GetSafeHandle();<br />
	if (hPal==NULL)<br />
		hPal = (HPALETTE) GetStockObject(DEFAULT_PALETTE);<br />
<br />
//***********************<br />
//At this point hPal is not NULL, is a valid handle to a palette<br />
//***********************<br />
<br />
	int f = ::GetLastError();<br />
<br />
//***********************<br />
// f == 0.  No error,  that's good!<br />
//***********************<br />
<br />
	// Get bitmap information<br />
	bitmap.GetObject(sizeof(bm),(LPSTR)&bm);<br />
<br />
	// Initialize the bitmapinfoheader<br />
	bi.biSize		= sizeof(BITMAPINFOHEADER);<br />
	bi.biWidth		= bm.bmWidth;<br />
	bi.biHeight 		= bm.bmHeight;<br />
	bi.biPlanes 		= 1;<br />
	bi.biBitCount		= bm.bmPlanes * bm.bmBitsPixel;<br />
	bi.biCompression	= dwCompression;<br />
	bi.biSizeImage		= 0;<br />
	bi.biXPelsPerMeter	= 0;<br />
	bi.biYPelsPerMeter	= 0;<br />
	bi.biClrUsed		= 0;<br />
	bi.biClrImportant	= 0;<br />
<br />
	// Compute the size of the  infoheader and the color table<br />
	int nColors = (1 << bi.biBitCount);<br />
	if( nColors > 256 ) <br />
		nColors = 0;<br />
	dwLen  = bi.biSize + nColors * sizeof(RGBQUAD);<br />
	<br />
	<br />
	// We need a device context to get the DIB from<br />
	hDC = (HDC)GetDC();<br />
<br />
//*********************<br />
//hDC is valid here<br />
//*********************<br />
<br />
	DWORD wx = ::GetDeviceCaps(hDC, RASTERCAPS);<br />
<br />
//*********************<br />
//  wx == 0,  no capabilities??  I'm reading about this function. still don't<br />
//  fully understand capabilities but am assuming not having any is not good<br />
//*********************<br />
<br />
	TRACE("Raster capabilities : %08X\n",wx);<br />
<br />
//*********************<br />
// hPal is still valid coming in here<br />
//*********************<br />
<br />
	hPal = SelectPalette(hDC,hPal,FALSE);<br />
<br />
//*********************<br />
// now all is lost, hPal is now NULL(0x00000000)<br />
// SelectPalette has failed.  because hDC has no capabilities?? <br />
//*********************<br />
<br />
	f = ::GetLastError();<br />
<br />
//*********************<br />
//  f == 6, 'The handle is invalid.'  Ok so my NULL handle is bad.  but why??<br />
//*********************<br />
<br />
	RealizePalette(hDC);<br />