winerr.h

这是一本学习 window编程的很好的参考教材

#ifndef __WIN_ERROR_CLASS_H___
#define __WIN_ERROR_CLASS_H___
#include <windows.h>
#include <string>

#ifndef tstring
	#ifdef _UNICODE
		#define tstring			std::wstring
	#else
		#define tstring			std::string		
	#endif
#endif

//////////////////////////////////////////////////////////
//	Desc:
//		Class wrapper for windows errors.  This class
//		allows easy translation of error codes into
//		readable strings however, in order for it to
//		work proper it must be given a correct
//		module handle if the error code is not
//		direct from system.
//////////////////////////////////////////////////////////
class CWinErr {
	public:
		CWinErr() {
			m_dwErr = 0;
			return;
		}

		CWinErr& operator = ( DWORD dwCode ) {
			m_dwErr = dwCode;
			return *this;
		}

		void SetCode( DWORD dwCode ) {
			m_dwErr = dwCode;
			return;
		}

		DWORD GetCode() {
			return m_dwErr;
		}

		operator DWORD(){
			return m_dwErr;
		}

		tstring GetFormattedMsg( LPCTSTR lpszModule = NULL ) 
		{
			DWORD	dwFmtRt		= 0;
			DWORD	dwFlags		= FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_FROM_SYSTEM;
			LPVOID	lpMsgBuf	= NULL;
			HMODULE hLookupMod	= NULL;
			tstring	sMsg		= _T("");

			if( lpszModule != NULL ) {
				hLookupMod	= ::LoadLibraryEx( lpszModule, NULL, LOAD_LIBRARY_AS_DATAFILE );
				if( hLookupMod ) {
					dwFlags	|=  FORMAT_MESSAGE_FROM_HMODULE;
				}				
			}

			dwFmtRt = ::FormatMessage( 
							dwFlags,
							( LPCVOID ) hLookupMod,
							m_dwErr,
							MAKELANGID( LANG_NEUTRAL, SUBLANG_DEFAULT ),
							(LPTSTR)&lpMsgBuf, 
							0,
							NULL );					
			
			
			if( dwFmtRt != 0 )	sMsg = ( TCHAR* ) lpMsgBuf;
			if( lpMsgBuf )		::LocalFree( lpMsgBuf );
			if( hLookupMod )	::FreeLibrary( hLookupMod );			

			return sMsg;
		}

	protected:
		DWORD m_dwErr;
};

#endif // __WIN_ERROR_CLASS_H___