string.h

用ATL写的操作数据库实例

	void AFX_CDECL Format(LPCTSTR lpszFormat, ...);
	// printf-like formatting using referenced string resource
	void AFX_CDECL Format(UINT nFormatID, ...);
	// printf-like formatting using variable arguments parameter
	void FormatV(LPCTSTR lpszFormat, va_list argList);

	// formatting for localization (uses FormatMessage API)

	// format using FormatMessage API on passed string
	void AFX_CDECL FormatMessage(LPCTSTR lpszFormat, ...);
	// format using FormatMessage API on referenced string resource
	void AFX_CDECL FormatMessage(UINT nFormatID, ...);

	// input and output

	// load from string resource
	BOOL LoadString(UINT nID);

#ifndef _UNICODE
	// ANSI <-> OEM support (convert string in place)

	// convert string from ANSI to OEM in-place
	void AnsiToOem();
	// convert string from OEM to ANSI in-place
	void OemToAnsi();
#endif

#ifndef _AFX_NO_BSTR_SUPPORT
	// OLE BSTR support (use for OLE automation)

	// return a BSTR initialized with this CString's data
	BSTR AllocSysString() const;
	// reallocates the passed BSTR, copies content of this CString to it
	BSTR SetSysString(BSTR* pbstr) const;
#endif

	// Access to string implementation buffer as "C" character array

	// get pointer to modifiable buffer at least as long as nMinBufLength
	LPTSTR GetBuffer(int nMinBufLength);
	// release buffer, setting length to nNewLength (or to first nul if -1)
	void ReleaseBuffer(int nNewLength = -1);
	// get pointer to modifiable buffer exactly as long as nNewLength
	LPTSTR GetBufferSetLength(int nNewLength);
	// release memory allocated to but unused by string
	void FreeExtra();

	// Use LockBuffer/UnlockBuffer to turn refcounting off

	// turn refcounting back on
	LPTSTR LockBuffer();
	// turn refcounting off
	void UnlockBuffer();

// Implementation
public:
	~CString();
	int GetAllocLength() const;

protected:
	LPTSTR m_pchData;   // pointer to ref counted string data

	// implementation helpers
	CStringData* GetData() const;
	void Init();
	void AllocCopy(CString& dest, int nCopyLen, int nCopyIndex, int nExtraLen) const;
	void AllocBuffer(int nLen);
	void AssignCopy(int nSrcLen, LPCTSTR lpszSrcData);
	void ConcatCopy(int nSrc1Len, LPCTSTR lpszSrc1Data, int nSrc2Len, LPCTSTR lpszSrc2Data);
	void ConcatInPlace(int nSrcLen, LPCTSTR lpszSrcData);
	void CopyBeforeWrite();
	void AllocBeforeWrite(int nLen);
	void Release();
	static void PASCAL Release(CStringData* pData);
	static int PASCAL SafeStrlen(LPCTSTR lpsz);
	static void FASTCALL FreeData(CStringData* pData);
};

// Compare helpers
bool AFXAPI operator==(const CString& s1, const CString& s2);
bool AFXAPI operator==(const CString& s1, LPCTSTR s2);
bool AFXAPI operator==(LPCTSTR s1, const CString& s2);
bool AFXAPI operator!=(const CString& s1, const CString& s2);
bool AFXAPI operator!=(const CString& s1, LPCTSTR s2);
bool AFXAPI operator!=(LPCTSTR s1, const CString& s2);
bool AFXAPI operator<(const CString& s1, const CString& s2);
bool AFXAPI operator<(const CString& s1, LPCTSTR s2);
bool AFXAPI operator<(LPCTSTR s1, const CString& s2);
bool AFXAPI operator>(const CString& s1, const CString& s2);
bool AFXAPI operator>(const CString& s1, LPCTSTR s2);
bool AFXAPI operator>(LPCTSTR s1, const CString& s2);
bool AFXAPI operator<=(const CString& s1, const CString& s2);
bool AFXAPI operator<=(const CString& s1, LPCTSTR s2);
bool AFXAPI operator<=(LPCTSTR s1, const CString& s2);
bool AFXAPI operator>=(const CString& s1, const CString& s2);
bool AFXAPI operator>=(const CString& s1, LPCTSTR s2);
bool AFXAPI operator>=(LPCTSTR s1, const CString& s2);

// conversion helpers
int AFX_CDECL _wcstombsz(char* mbstr, const wchar_t* wcstr, size_t count);
int AFX_CDECL _mbstowcsz(wchar_t* wcstr, const char* mbstr, size_t count);

// Globals
extern TCHAR afxChNil;
#ifdef _AFXDLL
const CString& AFXAPI AfxGetEmptyString();
#define afxEmptyString AfxGetEmptyString()
#else
extern LPCTSTR _afxPchNil;
#define afxEmptyString ((CString&)*(CString*)&_afxPchNil)
#endif
//------------------------------------------------------------------------------
// CString
_AFX_INLINE CStringData* CString::GetData() const
	{ ATLASSERT(m_pchData != NULL); return ((CStringData*)m_pchData)-1; }
_AFX_INLINE void CString::Init()
	{ m_pchData = afxEmptyString.m_pchData; }
#ifndef _AFXDLL
_AFX_INLINE CString::CString()
	{ m_pchData = afxEmptyString.m_pchData; }
#endif
_AFX_INLINE CString::CString(const unsigned char* lpsz)
	{ Init(); *this = (LPCSTR)lpsz; }
_AFX_INLINE const CString& CString::operator=(const unsigned char* lpsz)
	{ *this = (LPCSTR)lpsz; return *this; }
#ifdef _UNICODE
_AFX_INLINE const CString& CString::operator+=(char ch)
	{ *this += (TCHAR)ch; return *this; }
_AFX_INLINE const CString& CString::operator=(char ch)
	{ *this = (TCHAR)ch; return *this; }
_AFX_INLINE CString AFXAPI operator+(const CString& string, char ch)
	{ return string + (TCHAR)ch; }
_AFX_INLINE CString AFXAPI operator+(char ch, const CString& string)
	{ return (TCHAR)ch + string; }
#endif

_AFX_INLINE int CString::GetLength() const
	{ return GetData()->nDataLength; }
_AFX_INLINE int CString::GetAllocLength() const
	{ return GetData()->nAllocLength; }
_AFX_INLINE BOOL CString::IsEmpty() const
	{ return GetData()->nDataLength == 0; }
_AFX_INLINE CString::operator LPCTSTR() const
	{ return m_pchData; }
_AFX_INLINE int PASCAL CString::SafeStrlen(LPCTSTR lpsz)
	{ return (lpsz == NULL) ? 0 : lstrlen(lpsz); }

// CString support (windows specific)
_AFX_INLINE int CString::Compare(LPCTSTR lpsz) const
	{ ATLASSERT(AfxIsValidString(lpsz)); return _tcscmp(m_pchData, lpsz); }    // MBCS/Unicode aware
_AFX_INLINE int CString::CompareNoCase(LPCTSTR lpsz) const
	{ ATLASSERT(AfxIsValidString(lpsz)); return _tcsicmp(m_pchData, lpsz); }   // MBCS/Unicode aware
// CString::Collate is often slower than Compare but is MBSC/Unicode
//  aware as well as locale-sensitive with respect to sort order.
_AFX_INLINE int CString::Collate(LPCTSTR lpsz) const
	{ ATLASSERT(AfxIsValidString(lpsz)); return _tcscoll(m_pchData, lpsz); }   // locale sensitive
_AFX_INLINE int CString::CollateNoCase(LPCTSTR lpsz) const
	{ ATLASSERT(AfxIsValidString(lpsz)); return _tcsicoll(m_pchData, lpsz); }   // locale sensitive

_AFX_INLINE TCHAR CString::GetAt(int nIndex) const
{
	ATLASSERT(nIndex >= 0);
	ATLASSERT(nIndex < GetData()->nDataLength);
	return m_pchData[nIndex];
}
_AFX_INLINE TCHAR CString::operator[](int nIndex) const
{
	// same as GetAt
	ATLASSERT(nIndex >= 0);
	ATLASSERT(nIndex < GetData()->nDataLength);
	return m_pchData[nIndex];
}
_AFX_INLINE bool AFXAPI operator==(const CString& s1, const CString& s2)
	{ return s1.Compare(s2) == 0; }
_AFX_INLINE bool AFXAPI operator==(const CString& s1, LPCTSTR s2)
	{ return s1.Compare(s2) == 0; }
_AFX_INLINE bool AFXAPI operator==(LPCTSTR s1, const CString& s2)
	{ return s2.Compare(s1) == 0; }
_AFX_INLINE bool AFXAPI operator!=(const CString& s1, const CString& s2)
	{ return s1.Compare(s2) != 0; }
_AFX_INLINE bool AFXAPI operator!=(const CString& s1, LPCTSTR s2)
	{ return s1.Compare(s2) != 0; }
_AFX_INLINE bool AFXAPI operator!=(LPCTSTR s1, const CString& s2)
	{ return s2.Compare(s1) != 0; }
_AFX_INLINE bool AFXAPI operator<(const CString& s1, const CString& s2)
	{ return s1.Compare(s2) < 0; }
_AFX_INLINE bool AFXAPI operator<(const CString& s1, LPCTSTR s2)
	{ return s1.Compare(s2) < 0; }
_AFX_INLINE bool AFXAPI operator<(LPCTSTR s1, const CString& s2)
	{ return s2.Compare(s1) > 0; }
_AFX_INLINE bool AFXAPI operator>(const CString& s1, const CString& s2)
	{ return s1.Compare(s2) > 0; }
_AFX_INLINE bool AFXAPI operator>(const CString& s1, LPCTSTR s2)
	{ return s1.Compare(s2) > 0; }
_AFX_INLINE bool AFXAPI operator>(LPCTSTR s1, const CString& s2)
	{ return s2.Compare(s1) < 0; }
_AFX_INLINE bool AFXAPI operator<=(const CString& s1, const CString& s2)
	{ return s1.Compare(s2) <= 0; }
_AFX_INLINE bool AFXAPI operator<=(const CString& s1, LPCTSTR s2)
	{ return s1.Compare(s2) <= 0; }
_AFX_INLINE bool AFXAPI operator<=(LPCTSTR s1, const CString& s2)
	{ return s2.Compare(s1) >= 0; }
_AFX_INLINE bool AFXAPI operator>=(const CString& s1, const CString& s2)
	{ return s1.Compare(s2) >= 0; }
_AFX_INLINE bool AFXAPI operator>=(const CString& s1, LPCTSTR s2)
	{ return s1.Compare(s2) >= 0; }
_AFX_INLINE bool AFXAPI operator>=(LPCTSTR s1, const CString& s2)
	{ return s2.Compare(s1) <= 0; }