DLGTEMPLATE和DLGITEMTEMPLATE的使用

DLGTEMPLATE和DLGITEMTEMPLATE一般后面直接跟3个word数组，通常他们都是按照DWORD对齐的，三个数组分别表示menu、class和title，DLGITEMTEMPLATE是紧跟着DLGTEMPLATE出现的，可以有多个，每个表示DLGTEMPLATE中的一个控件。这个vc sample中的dlgtemp的示例中有介绍：

	// The first step is to allocate memory to define the dialog.  The information to be
	// stored in the allocated buffer is the following:
	//
	// 1.  DLGTEMPLATE structure
	// 2.    0x0000 (Word) indicating the dialog has no menu
	// 3.    0x0000 (Word) Let windows assign default class to the dialog
	// 4.    (Caption)  Null terminated unicode string
	// 5.    0x000B  (size of the font to be used)
	// 6.    "Arial"  (name of the typeface to be used)
	// 7.  DLGITEMTEMPLATE structure for the button  (HAS TO BE DWORD ALIGNED)
	// 8.    0x0080  to indicate the control is a button
	// 9.    (Title). Unicode null terminated string with the caption
	// 10.    0x0000   0 extra bytes of data for this control
	// 11.  DLGITEMTEMPLATE structure for the Static Text  (HAS TO BE DWORD ALIGNED)
	// 12.    0x0081 to indicate the control is static text
	// 13.   (Title). Unicode null terminated string with the text
	// 14     0x0000.  0 extra bytes of data for this control
	// 15. DLGITEMTEMPLATE structure for the Edit Control (HAS TO BE DWORD ALIGNED)
	// 16.   0x0082 to indicate an Edit control
	// 17.   (Text) - Null terminated unicode string to appear in the edit control
	// 18.   0x0000. 0 extra bytes of data for this control

	WCHAR szBoxCaption[] = L"Dialog Template Sample -  PRESS <ESC> TO CLOSE THIS DIALOG";
	WCHAR szFontName[] = L"ARIAL";

	// will first convert the control captions to UNICODE
	int     i;

	TRY  // catch memory exceptions and don't worry about allocation failures
	{
		// The following expressions have unnecessary parenthesis trying to make the
		// comments more clear.
		int nBufferSize =  sizeof(DLGTEMPLATE) + (2 * sizeof(WORD))/*menu and class*/ + sizeof(szBoxCaption);
		nBufferSize += sizeof(WORD) + sizeof(szFontName); /* font information*/

		nBufferSize = (nBufferSize + 3) & ~3;  // adjust size to make first control DWORD aligned

		for (i = 0; i < TOTALITEMS; i++)
		{
			int nItemLength = sizeof(DLGITEMTEMPLATE) + 3 * sizeof(WORD);
			nItemLength += (m_rgDlgItem[i].m_strCaption.GetLength() + 1) * sizeof(WCHAR);

			if (i != TOTALITEMS -1 )   // the last control does not need extra bytes
				nItemLength = (nItemLength + 3) & ~3;  // take into account gap so next control is DWORD aligned

			nBufferSize += nItemLength;
		}


		HLOCAL hLocal = LocalAlloc(LHND, nBufferSize);
		if (hLocal == NULL)
			AfxThrowMemoryException();

		BYTE*   pBuffer = (BYTE*)LocalLock(hLocal);
		if (pBuffer == NULL)
		{
			LocalFree(hLocal);
			AfxThrowMemoryException();
		}

		BYTE*   pdest = pBuffer;
		BYTE* pdestEnd = pdest + nBufferSize;
		// transfer DLGTEMPLATE structure to the buffer
		memcpy_s(pdest, pdestEnd - pdest, &m_dlgTempl, sizeof(DLGTEMPLATE));
		pdest += sizeof(DLGTEMPLATE);
		*(WORD*)pdest = 0; // no menu
		*(WORD*)(pdest + sizeof(WORD)) = 0;  // use default window class
		pdest += 2 * sizeof(WORD);
		memcpy_s(pdest, pdestEnd - pdest, szBoxCaption, sizeof(szBoxCaption));
		pdest += sizeof(szBoxCaption);
		*(WORD*)pdest = 11;  // font size
		pdest += sizeof(WORD);
		memcpy_s(pdest, pdestEnd - pdest, szFontName, sizeof(szFontName));
		pdest += sizeof(szFontName);

		// will now transfer the information for each one of the item templates
		for (i = 0; i < TOTALITEMS; i++)
		{
			pdest = (BYTE*)(((DWORD_PTR)pdest + 3) & ~3);  // make the pointer DWORD aligned
			memcpy_s(pdest, pdestEnd - pdest, (void *)&m_rgDlgItem[i].m_dlgItemTemplate, sizeof(DLGITEMTEMPLATE));
			pdest += sizeof(DLGITEMTEMPLATE);
			*(WORD*)pdest = 0xFFFF;  // indicating atom value
			pdest += sizeof(WORD);
			*(WORD*)pdest = (WORD)m_rgDlgItem[i].m_controltype;    // atom value for the control
			pdest += sizeof(WORD);

			// transfer the caption even when it is an empty string
			WCHAR*  pchCaption;
			int     nChars, nActualChars;

			nChars = m_rgDlgItem[i].m_strCaption.GetLength() + 1;
			pchCaption = new WCHAR[nChars];
			nActualChars = MultiByteToWideChar(CP_ACP, 0, m_rgDlgItem[i].m_strCaption, -1, pchCaption, nChars);
			ASSERT(nActualChars > 0);
			memcpy_s(pdest, pdestEnd - pdest, pchCaption, nActualChars * sizeof(WCHAR));
			pdest += nActualChars * sizeof(WCHAR);
			delete [] pchCaption;

			*(WORD*)pdest = 0;  // How many bytes in data for control
			pdest += sizeof(WORD);
		}
		ASSERT(pdest - pBuffer == nBufferSize); // just make sure we did not overrun the heap

		CDialog dlg;
		dlg.InitModalIndirect((DLGTEMPLATE*)pBuffer);
		dlg.DoModal();  // tadaaa!  this is the line everyone's been waiting for!!!

		LocalUnlock(hLocal);
		LocalFree(hLocal);
	}
	CATCH(CMemoryException, e)
	{
		MessageBox(NULL, _T("Memory allocation for dialog template failed.  Demo aborted!"),
			_T("Allocation Failure"), MB_ICONEXCLAMATION | MB_OK);
	}
	END_CATCH