CString源码

CString使用的是引用技术,可以共享数据(这个大家都知道),另外空的CStirng是指向一个固定的地址的(_afxInitData).
另外CStirng是有长度限制的2147483647(无符号int 的最大值).
数据格式
struct CStringData
{
 long nRefs; //引用记数
 int nDataLength; //字符使用长度
 int nAllocLength; //分配长度
 TCHAR* data() { return (TCHAR*)(this+1); } //存放字符串的地方
 //this+1 相当与是CStringData[1];所以TCHAR* data()指的是CStringData[1]的地址
};
基本和网络通讯的数据包差不多
typedef struct tagAnsMarketData //统一的应答结构
{
 WORD wStkNum; //数目
 char iData[1]; //数据

}ANS_MARKET_DATA,*PANS_MARKET_DATA;

#include <windows.h>#include <assert.h>#include <stdlib.h>#include <malloc.h>#include <tchar.h>string.h#ifndef __JONES__STRING__#define __JONES__STRING__struct CStringData{ long nRefs; //引用记数 int nDataLength; //字符使用长度 int nAllocLength; //分配长度 TCHAR* data() { return (TCHAR*)(this+1); } //存放字符串的地方 //this+1 相当与是CStringData[1];所以TCHAR* data()指的是CStringData[1]的地址};class CString{public: //构造函数 CString(); CString(const CString& stringSrc); CString(TCHAR ch, int nLength =1); CString(LPCTSTR lpsz); // CString(LPCSTR lpsz); ANSI下版本       //CString(LPCWSTR lpsz);UNICODE下版本 CString(LPCTSTR lpch, int nLength); //CString(LPCSTR lpch, int nLength);ANSI下版本          //CString(LPCWSTR lpch, int nLength);//UNICODE下版本 CString(const unsigned char* psz); ~CString(); //CStringData的属性 int GetLength() const; //得到字符长度 int GetAllocLength() const; //得到分配的内存长度 BOOL IsEmpty() const; //判断字符长度是否为0 operator LPCTSTR() const; //类型转换 void Empty(); //清空CStringData //操作符重载 const CString& operator=(const CString& stringSrc); const CString& operator=(LPCTSTR lpsz); const CString& operator=(TCHAR ch); const CString& operator+=(const CString& string); const CString& operator+=(TCHAR ch); const CString& operator+=(LPCTSTR lpsz); TCHAR operator[](int nIndex) const; friend CString operator+(const CString& string1,const CString& string2); friend CString operator+(const CString& string, TCHAR ch); friend CString operator+(TCHAR ch, const CString& string); friend CString operator+(const CString& string, LPCTSTR lpsz); friend CString operator+(LPCTSTR lpsz, const CString& string); //操作,脱离共享数据块 int Delete(int nIndex, int nCount = 1);//删除从nIndex开始长度为nCount的数据 int Insert(int nIndex, TCHAR ch); //插入一个字符 int Insert(int nIndex, LPCTSTR pstr); //插入一个字符串 int Replace(LPCTSTR lpszOld, LPCTSTR lpszNew); //替换数据 int Replace(TCHAR chOld, TCHAR chNew); //替换数据 int Remove(TCHAR chRemove); //移除一个字符 void TrimRight(LPCTSTR lpszTargetList); void TrimRight(TCHAR chTarget);//去掉右边chTarget void TrimRight(); //去掉右边空格 void TrimLeft(LPCTSTR lpszTargets); void TrimLeft(TCHAR chTarget); //去掉左边chTarget void TrimLeft(); //去掉左边空格 //取某段字符串 void SetAt(int nIndex, TCHAR ch); TCHAR GetAt(int nIndex) const; CString Mid(int nFirst) const; //取某段字符串 CString Mid(int nFirst, int nCount) const; //取某段字符串 CString Right(int nCount) const; //取右边字符串 CString Left(int nCount) const; //取左边字符串 void CString::MakeUpper(); //大写 void CString::MakeLower(); //小写 void CString::MakeReverse(); //????不知道干什么的 strrev //查找 int Find(TCHAR ch) const; int Find(TCHAR ch, int nStart) const; int ReverseFind(TCHAR ch) const; int Find(LPCTSTR lpszSub) const; int Find(LPCTSTR lpszSub, int nStart) const; int FindOneOf(LPCTSTR lpszCharSet) const;//得到第一个匹配lpszCharSet中其中一个字符的位置 调用_tcspbrk //高级操作 LPTSTR GetBuffer(int nMinBufLength); //重新分配内存,在拷贝原来的数据 void ReleaseBuffer(int nNewLength=-1); //在[nNewLength]='/0',对内存大小没有改变 LPTSTR GetBufferSetLength(int nNewLength); //重新分配内存,在拷贝原来的数据 void FreeExtra(); //深拷贝自己,然后--原来的引用记数器 LPTSTR LockBuffer(); //引用计数器=-1,加锁 void UnlockBuffer(); //解锁,引用计数器=1 //比较 int Compare(LPCTSTR lpsz) const; //区分大小写比较 int CompareNoCase(LPCTSTR lpsz) const; //不区分大小写比较 //比较速度没有Compare快 int Collate(LPCTSTR lpsz) const; //区分大小写比较 int CollateNoCase(LPCTSTR lpsz) const; //不区分大小写比较 //格式化字符串 void Format(LPCTSTR lpszFormat, ...);//CSting中最长的函数了,完全是自己分析的(牛啊)private: void Init(); CStringData* GetData() const; //通过m_pchData-1 得到CStringData void AllocBuffer(int nLen); //给CStringData分配内存,不带记数器 void CopyBeforeWrite(); //带引用记数的复制自己深拷贝 void AllocBeforeWrite(int nLen); //给CStringData分配内存,带记数器 void AssignCopy(int nSrcLen, LPCTSTR lpszSrcData);//分配内存,并拷贝lpszSrcData内容 //把nCopyIndex开始的nCopyLen长度的数据拷贝给dest,nExtraLen扩充的长度,次函数好像没下面用 void AllocCopy(CString& dest, int nCopyLen, int nCopyIndex,int nExtraLen) const; void Release(); //--引用记数器并判断是否删除内存,如删除并初始化 void FormatV(LPCTSTR lpszFormat, va_list argList);//格式化字符串 void ConcatCopy(int nSrc1Len, LPCTSTR lpszSrc1Data,  int nSrc2Len, LPCTSTR lpszSrc2Data);//连接数据lpszSrc1Data+lpszSrc2Data void ConcatInPlace(int nSrcLen, LPCTSTR lpszSrcData); //连接字符串 static void  Release(CStringData* pData); //--引用记数器并判断是否删除内存 static void FreeData(CStringData* pData); //释放内存 static int SafeStrlen(LPCTSTR lpsz); //得到长度 LPTSTR m_pchData; //指向CStringData的数据区};/*调用CString::Compare比较大小,如果比较中有CStirng的话用调用operator LPCTSTR()转化类型为LPCTSTR*/bool operator==(const CString& s1, const CString& s2);bool operator==(const CString& s1, LPCTSTR s2);bool operator==(LPCTSTR s1, const CString& s2);bool operator!=(const CString& s1, const CString& s2);bool operator!=(const CString& s1, LPCTSTR s2);bool operator!=(LPCTSTR s1, const CString& s2);bool operator<(const CString& s1, const CString& s2);bool operator<(const CString& s1, LPCTSTR s2);bool operator<(LPCTSTR s1, const CString& s2);bool operator>(const CString& s1, const CString& s2);bool operator>(const CString& s1, LPCTSTR s2);bool operator>(LPCTSTR s1, const CString& s2);bool operator<=(const CString& s1, const CString& s2);bool operator<=(const CString& s1, LPCTSTR s2);bool operator<=(LPCTSTR s1, const CString& s2);bool operator>=(const CString& s1, const CString& s2);bool operator>=(const CString& s1, LPCTSTR s2);bool operator>=(LPCTSTR s1, const CString& s2);////////////////////////////////////////////////////////////////////////检测lpsz是否有效,调用了IsBadStringPtrBOOL AfxIsValidString(LPCTSTR lpsz, int nLength = -1);//检测lp是否能读写权限,调用了IsBadReadPtr,IsBadStringPtrBOOL AfxIsValidAddress(const void* lp,UINT nBytes, BOOL bReadWrite = TRUE);//CStirng数组操作void ConstructElements(CString* pElements, int nCount); //初始化CStirng数组void DestructElements(CString* pElements, int nCount); //删除CStirng数组void CopyElements(CString* pDest, const CString* pSrc, int nCount); //CString数组拷贝#endifstring.cpp#include "stdafx.h"#include "string.h"TCHAR afxChNil = '/0';int _afxInitData[] = { -1, 0, 0, 0 }; //初始化CStringData的地址CStringData* _afxDataNil = (CStringData*)&_afxInitData; //地址转化为CStringData*LPCTSTR _afxPchNil = (LPCTSTR)(((BYTE*)&_afxInitData)+sizeof(CStringData));const CString&  AfxGetEmptyString()  //建立一个空的CString{ return *(CString*)&_afxPchNil; }BOOL AfxIsValidString(LPCTSTR lpsz, int nLength /* = -1 */){ if (lpsz == NULL)  return FALSE; return ::IsBadStringPtr(lpsz, nLength) == 0;}BOOL AfxIsValidAddress(const void* lp, UINT nBytes,BOOL bReadWrite /* = TRUE */){ return (lp != NULL && !IsBadReadPtr(lp, nBytes) &&  (!bReadWrite !IsBadWritePtr((LPVOID)lp, nBytes)));}void CString::Init(){ m_pchData=AfxGetEmptyString().m_pchData; }CString::CString(){ Init(); }int CString::GetLength() const{ return GetData()->nDataLength; }int CString::GetAllocLength() const{ return GetData()->nAllocLength; }BOOL CString::IsEmpty() const{ return GetData()->nDataLength == 0; }CStringData* CString::GetData() const{ assert(m_pchData != NULL); return ((CStringData*)m_pchData)-1;}CString::operator LPCTSTR() const{ return m_pchData; }int CString::SafeStrlen(LPCTSTR lpsz){ return (lpsz == NULL) ? 0 : lstrlen(lpsz); }void CString::AllocBuffer(int nLen){ assert(nLen >= 0); assert(nLen <= 2147483647-1);    // (signed) int 的最大值 if (nLen == 0)  Init(); else {  CStringData* pData;  {   pData = (CStringData*)    new BYTE[sizeof(CStringData) + (nLen+1)*sizeof(TCHAR)];   pData->nAllocLength = nLen;  }  pData->nRefs = 1;  pData->data()[nLen] = '/0';  pData->nDataLength = nLen;  m_pchData = pData->data(); }}void CString::FreeData(CStringData* pData){ delete[] (BYTE*)pData;}void CString::CopyBeforeWrite(){ if (GetData()->nRefs > 1) {  CStringData* pData = GetData();  Release();  AllocBuffer(pData->nDataLength);  memcpy(m_pchData, pData->data(), (pData->nDataLength+1)*sizeof(TCHAR)); } assert(GetData()->nRefs <= 1);}void CString::AllocBeforeWrite(int nLen){ if (GetData()->nRefs > 1 nLen > GetData()->nAllocLength) {  Release();  AllocBuffer(nLen); } assert(GetData()->nRefs <= 1);}void CString::AssignCopy(int nSrcLen, LPCTSTR lpszSrcData){ AllocBeforeWrite(nSrcLen); memcpy(m_pchData, lpszSrcData, nSrcLen*sizeof(TCHAR)); GetData()->nDataLength = nSrcLen; m_pchData[nSrcLen] = '/0';}void CString::AllocCopy(CString& dest, int nCopyLen, int nCopyIndex,  int nExtraLen) const{ int nNewLen = nCopyLen + nExtraLen; if (nNewLen == 0) {  dest.Init(); } else {  dest.AllocBuffer(nNewLen);  memcpy(dest.m_pchData, m_pchData+nCopyIndex, nCopyLen*sizeof(TCHAR)); }}CString::~CString(){ if (GetData() != _afxDataNil) {  if (InterlockedDecrement(&GetData()->nRefs) <= 0)   FreeData(GetData()); }}CString::CString(const CString& stringSrc){ assert(stringSrc.GetData()->nRefs != 0); if (stringSrc.GetData()->nRefs >= 0) {  assert(stringSrc.GetData() != _afxDataNil);  m_pchData = stringSrc.m_pchData;  InterlockedIncrement(&GetData()->nRefs); } else {  Init();  *this = stringSrc.m_pchData; }}CString::CString(LPCTSTR lpsz){ Init(); int nLen = SafeStrlen(lpsz); if (nLen != 0) {  AllocBuffer(nLen);  memcpy(m_pchData, lpsz, nLen*sizeof(TCHAR)); }}CString::CString(LPCTSTR lpch, int nLength){ Init(); if (nLength != 0) {  assert(AfxIsValidAddress(lpch, nLength, FALSE));  AllocBuffer(nLength);  memcpy(m_pchData, lpch, nLength*sizeof(TCHAR)); }}void CString::Release(){ if (GetData() != _afxDataNil) {  assert(GetData()->nRefs != 0);  if (InterlockedDecrement(&GetData()->nRefs) <= 0)   FreeData(GetData());  Init(); }}void CString::Release(CStringData* pData){ if (pData != _afxDataNil) {  assert(pData->nRefs != 0);  if (InterlockedDecrement(&pData->nRefs) <= 0)   FreeData(pData); }}void CString::Empty(){ if (GetData()->nDataLength == 0)  return; if (GetData()->nRefs >= 0)  Release(); else  *this = &afxChNil; assert(GetData()->nDataLength == 0); assert(GetData()->nRefs < 0 GetData()->nAllocLength == 0);}const CString& CString::operator=(const CString& stringSrc){ if (m_pchData != stringSrc.m_pchData) {  if ((GetData()->nRefs < 0 && GetData() != _afxDataNil)   stringSrc.GetData()->nRefs < 0)  {   //新建一快数据   AssignCopy(stringSrc.GetData()->nDataLength, stringSrc.m_pchData);  }  else  {   //只拷贝指针   Release();   assert(stringSrc.GetData() != _afxDataNil);   m_pchData = stringSrc.m_pchData;   InterlockedIncrement(&GetData()->nRefs);  } } return *this;}const CString& CString::operator=(LPCTSTR lpsz){ assert(lpsz == NULL AfxIsValidString(lpsz)); AssignCopy(SafeStrlen(lpsz), lpsz); return *this;}const CString& CString::operator=(TCHAR ch){ AssignCopy(1, &ch); return *this;}int CString::Delete(int nIndex, int nCount /* = 1 */){ if (nIndex < 0)  nIndex = 0; int nNewLength = GetData()->nDataLength; if (nCount > 0 && nIndex < nNewLength) {  CopyBeforeWrite(); //脱离共享数据块，  int nBytesToCopy = nNewLength - (nIndex + nCount) + 1;  //移动数据  memcpy(m_pchData + nIndex,   m_pchData + nIndex + nCount, nBytesToCopy * sizeof(TCHAR));  GetData()->nDataLength = nNewLength - nCount; } return nNewLength;}int CString::Insert(int nIndex, TCHAR ch){ CopyBeforeWrite(); //脱离共享数据 if (nIndex < 0)  nIndex = 0; int nNewLength = GetData()->nDataLength; if (nIndex > nNewLength)  nIndex = nNewLength; nNewLength++; if (GetData()->nAllocLength < nNewLength) { //动态分配内存,并拷贝原来的数据  CStringData* pOldData = GetData();  LPTSTR pstr = m_pchData;  AllocBuffer(nNewLength);  memcpy(m_pchData, pstr, (pOldData->nDataLength+1)*sizeof(TCHAR));  CString::Release(pOldData); } //插入数据 memcpy(m_pchData + nIndex + 1,  m_pchData + nIndex, (nNewLength-nIndex)*sizeof(TCHAR)); m_pchData[nIndex] = ch; GetData()->nDataLength = nNewLength; return nNewLength;}int CString::Insert(int nIndex, LPCTSTR pstr){ if (nIndex < 0)  nIndex = 0; int nInsertLength = SafeStrlen(pstr); int nNewLength = GetData()->nDataLength; if (nInsertLength > 0) {  CopyBeforeWrite(); //脱离共享数据  if (nIndex > nNewLength)   nIndex = nNewLength;  nNewLength += nInsertLength;  if (GetData()->nAllocLength < nNewLength)  { //动态分配内存,并拷贝原来的数据   CStringData* pOldData = GetData();   LPTSTR pstr = m_pchData;   AllocBuffer(nNewLength);   memcpy(m_pchData, pstr, (pOldData->nDataLength+1)*sizeof(TCHAR));   CString::Release(pOldData);  }  //移动数据，留出插入的位move也可以  memcpy(m_pchData + nIndex + nInsertLength,   m_pchData + nIndex,   (nNewLength-nIndex-nInsertLength+1)*sizeof(TCHAR));  //插入数据  memcpy(m_pchData + nIndex,   pstr, nInsertLength*sizeof(TCHAR));  GetData()->nDataLength = nNewLength; } return nNewLength;}int CString::Replace(TCHAR chOld, TCHAR chNew){ int nCount = 0; if (chOld != chNew) //替换的不能相同 {  CopyBeforeWrite();  LPTSTR psz = m_pchData;  LPTSTR pszEnd = psz + GetData()->nDataLength;  while (psz < pszEnd)  {   if (*psz == chOld) //替换   {    *psz = chNew;    nCount++;   }   psz = _tcsinc(psz); //相当于++psz,考虑要UNICODE下版本才用的  } } return nCount;}int CString::Replace(LPCTSTR lpszOld, LPCTSTR lpszNew){ int nSourceLen = SafeStrlen(lpszOld); if (nSourceLen == 0) //要替换的不能为空  return 0; int nReplacementLen = SafeStrlen(lpszNew); int nCount = 0; LPTSTR lpszStart = m_pchData; LPTSTR lpszEnd = m_pchData + GetData()->nDataLength; LPTSTR lpszTarget; while (lpszStart < lpszEnd) //检索要替换的个数 {  while ((lpszTarget = _tcsstr(lpszStart, lpszOld)) != NULL)  {   nCount++;   lpszStart = lpszTarget + nSourceLen;  }  lpszStart += lstrlen(lpszStart) + 1; }  if (nCount > 0) {  CopyBeforeWrite();  int nOldLength = GetData()->nDataLength;  int nNewLength =  nOldLength + (nReplacementLen-nSourceLen)*nCount; //替换以后的长度  if (GetData()->nAllocLength < nNewLength GetData()->nRefs > 1)  { //超出原来的内存长度动态分配   CStringData* pOldData = GetData();   LPTSTR pstr = m_pchData;   AllocBuffer(nNewLength);   memcpy(m_pchData, pstr, pOldData->nDataLength*sizeof(TCHAR));   CString::Release(pOldData);  }   lpszStart = m_pchData;  lpszEnd = m_pchData + GetData()->nDataLength;   while (lpszStart < lpszEnd) //这个循环好象没什么用  {   while ( (lpszTarget = _tcsstr(lpszStart, lpszOld)) != NULL) //开始替换   {    int nBalance = nOldLength - (lpszTarget - m_pchData + nSourceLen); //要往后移的长度    //移动数据，留出插入的位    memmove(lpszTarget + nReplacementLen, lpszTarget + nSourceLen,     nBalance * sizeof(TCHAR));    //插入替换数据    memcpy(lpszTarget, lpszNew, nReplacementLen*sizeof(TCHAR));    lpszStart = lpszTarget + nReplacementLen;    lpszStart[nBalance] = '/0';    nOldLength += (nReplacementLen - nSourceLen); //现有数据长度   }   lpszStart += lstrlen(lpszStart) + 1;  }  assert(m_pchData[nNewLength] == '/0');  GetData()->nDataLength = nNewLength; } return nCount;}int CString::Remove(TCHAR chRemove){ CopyBeforeWrite(); LPTSTR pstrSource = m_pchData; LPTSTR pstrDest = m_pchData; LPTSTR pstrEnd = m_pchData + GetData()->nDataLength; while (pstrSource < pstrEnd) {  if (*pstrSource != chRemove)  {   *pstrDest = *pstrSource; //把不移除的数据拷贝   pstrDest = _tcsinc(pstrDest);  }  pstrSource = _tcsinc(pstrSource);//++pstrSource } *pstrDest = '/0'; int nCount = pstrSource - pstrDest; //比较变态的计算替换个数, GetData()->nDataLength -= nCount; return nCount;}CString CString::Mid(int nFirst) const{ return Mid(nFirst, GetData()->nDataLength - nFirst);}CString CString::Mid(int nFirst, int nCount) const{ if (nFirst < 0)  nFirst = 0; if (nCount < 0)  nCount = 0; if (nFirst + nCount > GetData()->nDataLength)  nCount = GetData()->nDataLength - nFirst; if (nFirst > GetData()->nDataLength)  nCount = 0; assert(nFirst >= 0); assert(nFirst + nCount <= GetData()->nDataLength); //取去整个数据 if (nFirst == 0 && nFirst + nCount == GetData()->nDataLength)  return *this;  CString dest; AllocCopy(dest, nCount, nFirst, 0); return dest;}CString CString::Right(int nCount) const{ if (nCount < 0)  nCount = 0; if (nCount >= GetData()->nDataLength)  return *this; CString dest; AllocCopy(dest, nCount, GetData()->nDataLength-nCount, 0); return dest;}CString CString::Left(int nCount) const{ if (nCount < 0)  nCount = 0; if (nCount >= GetData()->nDataLength)  return *this; CString dest; AllocCopy(dest, nCount, 0, 0); return dest;}int CString::ReverseFind(TCHAR ch) const{ //从最后查找 LPTSTR lpsz = _tcsrchr(m_pchData, (_TUCHAR) ch); return (lpsz == NULL) ? -1 : (int)(lpsz - m_pchData);}int CString::Find(TCHAR ch) const{ return Find(ch, 0);}int CString::Find(TCHAR ch, int nStart) const{ int nLength = GetData()->nDataLength; if (nStart >= nLength)  return -1; LPTSTR lpsz = _tcschr(m_pchData + nStart, (_TUCHAR)ch); return (lpsz == NULL) ? -1 : (int)(lpsz - m_pchData);}int CString::Find(LPCTSTR lpszSub) const{ return Find(lpszSub, 0);}int CString::Find(LPCTSTR lpszSub, int nStart) const{ assert(AfxIsValidString(lpszSub)); int nLength = GetData()->nDataLength; if (nStart > nLength)  return -1; LPTSTR lpsz = _tcsstr(m_pchData + nStart, lpszSub); return (lpsz == NULL) ? -1 : (int)(lpsz - m_pchData);}int CString::FindOneOf(LPCTSTR lpszCharSet) const{ assert(AfxIsValidString(lpszCharSet)); LPTSTR lpsz = _tcspbrk(m_pchData, lpszCharSet); return (lpsz == NULL) ? -1 : (int)(lpsz - m_pchData);}void CString::MakeUpper(){ CopyBeforeWrite(); _tcsupr(m_pchData);}void CString::MakeLower(){ CopyBeforeWrite(); _tcslwr(m_pchData);}void CString::MakeReverse(){ CopyBeforeWrite(); _tcsrev(m_pchData);}void CString::SetAt(int nIndex, TCHAR ch){ assert(nIndex >= 0); assert(nIndex < GetData()->nDataLength); CopyBeforeWrite(); m_pchData[nIndex] = ch;}void CString::TrimRight(LPCTSTR lpszTargetList){ CopyBeforeWrite(); LPTSTR lpsz = m_pchData; LPTSTR lpszLast = NULL; while (*lpsz != '/0') {  if (_tcschr(lpszTargetList, *lpsz) != NULL)  {   if (lpszLast == NULL)    lpszLast = lpsz;  }  else   lpszLast = NULL;  lpsz = _tcsinc(lpsz); } if (lpszLast != NULL) {  *lpszLast = '/0';  GetData()->nDataLength = lpszLast - m_pchData; }}void CString::TrimRight(TCHAR chTarget){ CopyBeforeWrite(); LPTSTR lpsz = m_pchData; LPTSTR lpszLast = NULL; while (*lpsz != '/0') {  if (*lpsz == chTarget)  {   if (lpszLast == NULL)    lpszLast = lpsz;  }  else   lpszLast = NULL;  lpsz = _tcsinc(lpsz); } if (lpszLast != NULL) {  *lpszLast = '/0';  GetData()->nDataLength = lpszLast - m_pchData; }}void CString::TrimRight(){ CopyBeforeWrite(); LPTSTR lpsz = m_pchData; LPTSTR lpszLast = NULL; while (*lpsz != '/0') {  if (_istspace(*lpsz))  {   if (lpszLast == NULL)    lpszLast = lpsz;  }  else   lpszLast = NULL;  lpsz = _tcsinc(lpsz); } if (lpszLast != NULL) {  // truncate at trailing space start  *lpszLast = '/0';  GetData()->nDataLength = lpszLast - m_pchData; }}void CString::TrimLeft(LPCTSTR lpszTargets){ // if we're not trimming anything, we're not doing any work if (SafeStrlen(lpszTargets) == 0)  return; CopyBeforeWrite(); LPCTSTR lpsz = m_pchData; while (*lpsz != '/0') {  if (_tcschr(lpszTargets, *lpsz) == NULL)   break;  lpsz = _tcsinc(lpsz); } if (lpsz != m_pchData) {  // fix up data and length  int nDataLength = GetData()->nDataLength - (lpsz - m_pchData);  memmove(m_pchData, lpsz, (nDataLength+1)*sizeof(TCHAR));  GetData()->nDataLength = nDataLength; }}void CString::TrimLeft(TCHAR chTarget){ CopyBeforeWrite(); LPCTSTR lpsz = m_pchData; while (chTarget == *lpsz)  lpsz = _tcsinc(lpsz); if (lpsz != m_pchData) {  int nDataLength = GetData()->nDataLength - (lpsz - m_pchData);  memmove(m_pchData, lpsz, (nDataLength+1)*sizeof(TCHAR));  GetData()->nDataLength = nDataLength; }}void CString::TrimLeft(){ CopyBeforeWrite(); LPCTSTR lpsz = m_pchData; while (_istspace(*lpsz))  lpsz = _tcsinc(lpsz); if (lpsz != m_pchData) {  int nDataLength = GetData()->nDataLength - (lpsz - m_pchData);  memmove(m_pchData, lpsz, (nDataLength+1)*sizeof(TCHAR));  GetData()->nDataLength = nDataLength; }}#define TCHAR_ARG   TCHAR#define WCHAR_ARG   WCHAR#define CHAR_ARG    charstruct _AFX_DOUBLE  { BYTE doubleBits[sizeof(double)]; };#ifdef _X86_ #define DOUBLE_ARG  _AFX_DOUBLE#else #define DOUBLE_ARG  double#endif#define FORCE_ANSI      0x10000#define FORCE_UNICODE   0x20000#define FORCE_INT64     0x40000void CString::FormatV(LPCTSTR lpszFormat, va_list argList){ assert(AfxIsValidString(lpszFormat)); va_list argListSave = argList; // make a guess at the maximum length of the resulting string int nMaxLen = 0; for (LPCTSTR lpsz = lpszFormat; *lpsz != '/0'; lpsz = _tcsinc(lpsz)) {  //查找%,对%%不在查找范围  if (*lpsz != '%' *(lpsz = _tcsinc(lpsz)) == '%')  {   nMaxLen += _tclen(lpsz);   continue;  }  int nItemLen = 0;  //%后面的格式判断  int nWidth = 0;  for (; *lpsz != '/0'; lpsz = _tcsinc(lpsz))  {   if (*lpsz == '#')    nMaxLen += 2;   // 16进制 '0x'   else if (*lpsz == '*')    nWidth = va_arg(argList, int);   else if (*lpsz == '-' *lpsz == '+' *lpsz == '0'    *lpsz == ' ')    ;   else // hit non-flag character    break;  }  // get width and skip it  if (nWidth == 0)  {   // width indicated by   nWidth = _ttoi(lpsz);   for (; *lpsz != '/0' && _istdigit(*lpsz); lpsz = _tcsinc(lpsz))    ;  }  assert(nWidth >= 0);  int nPrecision = 0;  if (*lpsz == '.')  {   // skip past '.' separator (width.precision)   lpsz = _tcsinc(lpsz);   // get precision and skip it   if (*lpsz == '*')   {    nPrecision = va_arg(argList, int);    lpsz = _tcsinc(lpsz);   }   else   {    nPrecision = _ttoi(lpsz);    for (; *lpsz != '/0' && _istdigit(*lpsz); lpsz = _tcsinc(lpsz))     ;   }   assert(nPrecision >= 0);  }  // should be on type modifier or specifier  int nModifier = 0;  if (_tcsncmp(lpsz, _T("I64"), 3) == 0)  {   lpsz += 3;   nModifier = FORCE_INT64;#if !defined(_X86_) && !defined(_ALPHA_)   // __int64 is only available on X86 and ALPHA platforms   ASSERT(FALSE);#endif  }  else  {   switch (*lpsz)   {   // modifiers that affect size   case 'h':    nModifier = FORCE_ANSI;    lpsz = _tcsinc(lpsz);    break;   case 'l':    nModifier = FORCE_UNICODE;    lpsz = _tcsinc(lpsz);    break;   // modifiers that do not affect size   case 'F':   case 'N':   case 'L':    lpsz = _tcsinc(lpsz);    break;   }  }  // now should be on specifier  switch (*lpsz | nModifier)  {  // single characters  case 'c':  case 'C':   nItemLen = 2;   va_arg(argList, TCHAR_ARG);   break;  case 'c'|FORCE_ANSI:  case 'C'|FORCE_ANSI:   nItemLen = 2;   va_arg(argList, CHAR_ARG);   break;  case 'c'|FORCE_UNICODE:  case 'C'|FORCE_UNICODE:   nItemLen = 2;   va_arg(argList, WCHAR_ARG);   break;  // strings  case 's':   {    LPCTSTR pstrNextArg = va_arg(argList, LPCTSTR);    if (pstrNextArg == NULL)       nItemLen = 6;  // "(null)"    else    {       nItemLen = lstrlen(pstrNextArg);       nItemLen = max(1, nItemLen);    }   }   break;  case 'S':   {#ifndef _UNICODE    LPWSTR pstrNextArg = va_arg(argList, LPWSTR);    if (pstrNextArg == NULL)       nItemLen = 6;  // "(null)"    else    {       nItemLen = wcslen(pstrNextArg);       nItemLen = max(1, nItemLen);    }#else    LPCSTR pstrNextArg = va_arg(argList, LPCSTR);    if (pstrNextArg == NULL)       nItemLen = 6; // "(null)"    else    {       nItemLen = lstrlenA(pstrNextArg);       nItemLen = max(1, nItemLen);    }#endif   }   break;  case 's'|FORCE_ANSI:  case 'S'|FORCE_ANSI:   {    LPCSTR pstrNextArg = va_arg(argList, LPCSTR);    if (pstrNextArg == NULL)       nItemLen = 6; // "(null)"    else    {       nItemLen = lstrlenA(pstrNextArg);       nItemLen = max(1, nItemLen);    }   }   break;  case 's'|FORCE_UNICODE:  case 'S'|FORCE_UNICODE:   {    LPWSTR pstrNextArg = va_arg(argList, LPWSTR);    if (pstrNextArg == NULL)       nItemLen = 6; // "(null)"    else    {       nItemLen = wcslen(pstrNextArg);       nItemLen = max(1, nItemLen);    }   }   break;  }  // adjust nItemLen for strings  if (nItemLen != 0)  {   if (nPrecision != 0)    nItemLen = min(nItemLen, nPrecision);   nItemLen = max(nItemLen, nWidth);  }  else  {   switch (*lpsz)   {   // integers   case 'd':   case 'i':   case 'u':   case 'x':   case 'X':   case 'o':    if (nModifier & FORCE_INT64)     va_arg(argList, __int64);    else     va_arg(argList, int);    nItemLen = 32;    nItemLen = max(nItemLen, nWidth+nPrecision);    break;   case 'e':   case 'g':   case 'G':    va_arg(argList, DOUBLE_ARG);    nItemLen = 128;    nItemLen = max(nItemLen, nWidth+nPrecision);    break;   case 'f':    {     double f;     LPTSTR pszTemp;     // 312 == strlen("-1+(309 zeroes).")     // 309 zeroes == max precision of a double     // 6 == adjustment in case precision is not specified,     //   which means that the precision defaults to 6     pszTemp = (LPTSTR)_alloca(max(nWidth, 312+nPrecision+6));     f = va_arg(argList, double);     _stprintf( pszTemp, _T( "%*.*f" ), nWidth, nPrecision+6, f );     nItemLen = _tcslen(pszTemp);    }    break;   case 'p':    va_arg(argList, void*);    nItemLen = 32;    nItemLen = max(nItemLen, nWidth+nPrecision);    break;   // no output   case 'n':    va_arg(argList, int*);    break;   default:    assert(FALSE);  // unknown formatting option   }  }  // adjust nMaxLen for output nItemLen  nMaxLen += nItemLen; } GetBuffer(nMaxLen); //VERIFY(_vstprintf(m_pchData, lpszFormat, argListSave) <= GetAllocLength()); _vstprintf(m_pchData, lpszFormat, argListSave); ReleaseBuffer(); va_end(argListSave);}void CString::Format(LPCTSTR lpszFormat, ...){ assert(AfxIsValidString(lpszFormat)); va_list argList; va_start(argList, lpszFormat); FormatV(lpszFormat, argList); va_end(argList);}void CString::ConcatCopy(int nSrc1Len, LPCTSTR lpszSrc1Data,int nSrc2Len, LPCTSTR lpszSrc2Data){ int nNewLen = nSrc1Len + nSrc2Len; if (nNewLen != 0) {  AllocBuffer(nNewLen);  memcpy(m_pchData, lpszSrc1Data, nSrc1Len*sizeof(TCHAR));  memcpy(m_pchData+nSrc1Len, lpszSrc2Data, nSrc2Len*sizeof(TCHAR)); }}void CString::ConcatInPlace(int nSrcLen, LPCTSTR lpszSrcData){ if (nSrcLen == 0)  return;  if (GetData()->nRefs > 1 GetData()->nDataLength + nSrcLen > GetData()->nAllocLength) {//动态分配  CStringData* pOldData = GetData();  ConcatCopy(GetData()->nDataLength, m_pchData, nSrcLen, lpszSrcData);  assert(pOldData != NULL);  CString::Release(pOldData); } else {//直接往后添加  memcpy(m_pchData+GetData()->nDataLength, lpszSrcData, nSrcLen*sizeof(TCHAR));  GetData()->nDataLength += nSrcLen;  assert(GetData()->nDataLength <= GetData()->nAllocLength);  m_pchData[GetData()->nDataLength] = '/0'; }}const CString& CString::operator+=(LPCTSTR lpsz){ assert(lpsz == NULL AfxIsValidString(lpsz)); ConcatInPlace(SafeStrlen(lpsz), lpsz); return *this;}const CString& CString::operator+=(TCHAR ch){ ConcatInPlace(1, &ch); return *this;}const CString& CString::operator+=(const CString& string){ ConcatInPlace(string.GetData()->nDataLength, string.m_pchData); return *this;}LPTSTR CString::GetBuffer(int nMinBufLength){ assert(nMinBufLength >= 0); if (GetData()->nRefs > 1 nMinBufLength > GetData()->nAllocLength) { //重新动态分配  CStringData* pOldData = GetData();  int nOldLen = GetData()->nDataLength;   // AllocBuffer will tromp it  if (nMinBufLength < nOldLen)   nMinBufLength = nOldLen;  AllocBuffer(nMinBufLength);  memcpy(m_pchData, pOldData->data(), (nOldLen+1)*sizeof(TCHAR));  GetData()->nDataLength = nOldLen;  CString::Release(pOldData); } assert(GetData()->nRefs <= 1); assert(m_pchData != NULL); return m_pchData;}void CString::ReleaseBuffer(int nNewLength){ CopyBeforeWrite();  //脱离共享数据块， if (nNewLength == -1)  nNewLength = lstrlen(m_pchData); // zero terminated assert(nNewLength <= GetData()->nAllocLength); GetData()->nDataLength = nNewLength; m_pchData[nNewLength] = '/0';}LPTSTR CString::GetBufferSetLength(int nNewLength){ assert(nNewLength >= 0); GetBuffer(nNewLength); GetData()->nDataLength = nNewLength; m_pchData[nNewLength] = '/0'; return m_pchData;}void CString::FreeExtra(){ assert(GetData()->nDataLength <= GetData()->nAllocLength); if (GetData()->nDataLength != GetData()->nAllocLength) {  CStringData* pOldData = GetData();  AllocBuffer(GetData()->nDataLength);  memcpy(m_pchData, pOldData->data(), pOldData->nDataLength*sizeof(TCHAR));  assert(m_pchData[GetData()->nDataLength] == '/0');  CString::Release(pOldData); } assert(GetData() != NULL);}LPTSTR CString::LockBuffer(){ LPTSTR lpsz = GetBuffer(0); GetData()->nRefs = -1; return lpsz;}void CString::UnlockBuffer(){ assert(GetData()->nRefs == -1); if (GetData() != _afxDataNil)  GetData()->nRefs = 1;}int CString::Compare(LPCTSTR lpsz) const{ assert(AfxIsValidString(lpsz)); return _tcscmp(m_pchData, lpsz);}int CString::CompareNoCase(LPCTSTR lpsz) const{ assert(AfxIsValidString(lpsz)); return _tcsicmp(m_pchData, lpsz);} // CString::Collate is often slower than Compare but is MBSC/Unicode//  aware as well as locale-sensitive with respect to sort order.int CString::Collate(LPCTSTR lpsz) const{ assert(AfxIsValidString(lpsz)); return _tcscoll(m_pchData, lpsz);} int CString::CollateNoCase(LPCTSTR lpsz) const{ assert(AfxIsValidString(lpsz)); return _tcsicoll(m_pchData, lpsz);} TCHAR CString::GetAt(int nIndex) const{ assert(nIndex >= 0); assert(nIndex < GetData()->nDataLength); return m_pchData[nIndex];}TCHAR CString::operator[](int nIndex) const{ assert(nIndex >= 0); assert(nIndex < GetData()->nDataLength); return m_pchData[nIndex];}////////////////////////////////////////////////////////////////////////////////CString operator+(const CString& string1, const CString& string2){ CString s; s.ConcatCopy(string1.GetData()->nDataLength, string1.m_pchData,  string2.GetData()->nDataLength, string2.m_pchData); return s;}CString operator+(const CString& string, LPCTSTR lpsz){ assert(lpsz == NULL AfxIsValidString(lpsz)); CString s; s.ConcatCopy(string.GetData()->nDataLength, string.m_pchData,  CString::SafeStrlen(lpsz), lpsz); return s;}CString operator+(LPCTSTR lpsz, const CString& string){ assert(lpsz == NULL AfxIsValidString(lpsz)); CString s; s.ConcatCopy(CString::SafeStrlen(lpsz), lpsz, string.GetData()->nDataLength,  string.m_pchData); return s;}bool operator==(const CString& s1, const CString& s2){ return s1.Compare(s2) == 0; }bool operator==(const CString& s1, LPCTSTR s2){ return s1.Compare(s2) == 0; }bool operator==(LPCTSTR s1, const CString& s2){ return s2.Compare(s1) == 0; }bool operator!=(const CString& s1, const CString& s2){ return s1.Compare(s2) != 0; }bool operator!=(const CString& s1, LPCTSTR s2){ return s1.Compare(s2) != 0; }bool operator!=(LPCTSTR s1, const CString& s2){ return s2.Compare(s1) != 0; }bool operator<(const CString& s1, const CString& s2){ return s1.Compare(s2) < 0; }bool operator<(const CString& s1, LPCTSTR s2){ return s1.Compare(s2) < 0; }bool operator<(LPCTSTR s1, const CString& s2){ return s2.Compare(s1) > 0; }bool operator>(const CString& s1, const CString& s2){ return s1.Compare(s2) > 0; }bool operator>(const CString& s1, LPCTSTR s2){ return s1.Compare(s2) > 0; }bool operator>(LPCTSTR s1, const CString& s2){ return s2.Compare(s1) < 0; }bool operator<=(const CString& s1, const CString& s2){ return s1.Compare(s2) <= 0; }bool operator<=(const CString& s1, LPCTSTR s2){ return s1.Compare(s2) <= 0; }bool operator<=(LPCTSTR s1, const CString& s2){ return s2.Compare(s1) >= 0; }bool operator>=(const CString& s1, const CString& s2){ return s1.Compare(s2) >= 0; }bool operator>=(const CString& s1, LPCTSTR s2){ return s1.Compare(s2) >= 0; }bool operator>=(LPCTSTR s1, const CString& s2){ return s2.Compare(s1) <= 0; }////////////////////////////////////////////////////////////////////////////////void ConstructElements(CString* pElements, int nCount){ assert(nCount == 0  AfxIsValidAddress(pElements, nCount * sizeof(CString))); for (; nCount--; ++pElements)  memcpy(pElements, &AfxGetEmptyString(), sizeof(*pElements));}void DestructElements(CString* pElements, int nCount){ assert(nCount == 0  AfxIsValidAddress(pElements, nCount * sizeof(CString))); for (; nCount--; ++pElements)  pElements->~CString();} void CopyElements(CString* pDest, const CString* pSrc, int nCount){ assert(nCount == 0  AfxIsValidAddress(pDest, nCount * sizeof(CString))); assert(nCount == 0  AfxIsValidAddress(pSrc, nCount * sizeof(CString))); for (; nCount--; ++pDest, ++pSrc)  *pDest = *pSrc;}