c++编写字符串编码类
废话不多说，上代码：
#include <iostream>#include <string>#include <windows.h>using namespace std;class CEncodeString{public:CEncodeString();~CEncodeString();void LoadString(char *,int =ansi);void LoadString(WCHAR *);enum{ansi,unicode,utf8};wstring ToUnicode();string ToAnsi();string ToUtf8();string GetUnicodeHeader();string GetUtf8Header();private:string m_str;};CEncodeString::CEncodeString(){}CEncodeString::~CEncodeString(){}void CEncodeString::LoadString(char *str,int mode/* =ansi */){if(mode==ansi){string strTemp;strTemp+=str[0];strTemp+=str[1];if(strTemp==GetUnicodeHeader()){LoadString((WCHAR*)(str+2));return;}strTemp+=str[2];if(strTemp==GetUtf8Header()){str+=3;mode=utf8;}else{m_str=str;}}if(mode==utf8){int wcsLen = ::MultiByteToWideChar(CP_UTF8, NULL, str, strlen(str), NULL, 0); wchar_t* wszString = new wchar_t[wcsLen + 1]; ::MultiByteToWideChar(CP_UTF8, NULL, str, strlen(str), wszString, wcsLen); wszString[wcsLen] = '\0'; int ansiLen = ::WideCharToMultiByte(CP_ACP, NULL, wszString, wcslen(wszString), NULL, 0, NULL, NULL); char* szAnsi = new char[ansiLen + 1]; ::WideCharToMultiByte(CP_ACP, NULL, wszString, wcslen(wszString), szAnsi, ansiLen, NULL, NULL); szAnsi[ansiLen] = '\0'; m_str=szAnsi;delete[] wszString;delete[] szAnsi;}}void CEncodeString::LoadString(WCHAR *wStr){int ansiLen = ::WideCharToMultiByte(CP_ACP, NULL, wStr, wcslen(wStr), NULL, 0, NULL, NULL); char* szAnsi = new char[ansiLen + 1]; ::WideCharToMultiByte(CP_ACP, NULL, wStr, wcslen(wStr), szAnsi, ansiLen, NULL, NULL); szAnsi[ansiLen] = '\0'; m_str=szAnsi;delete[] szAnsi;}wstring CEncodeString::ToUnicode(){char* szAnsi =(char*)m_str.data(); int wcsLen = ::MultiByteToWideChar(CP_ACP, NULL, szAnsi, strlen(szAnsi), NULL, 0); wchar_t* wszString = new wchar_t[wcsLen + 1]; ::MultiByteToWideChar(CP_ACP, NULL, szAnsi, strlen(szAnsi), wszString, wcsLen); wszString[wcsLen] = '\0'; wstring wStr=wszString;delete[] wszString;return wStr;}string CEncodeString::ToAnsi(){return m_str;}string CEncodeString::ToUtf8(){wstring wStr=ToUnicode();wchar_t* wszString =(wchar_t*) wStr.data(); int u8Len = ::WideCharToMultiByte(CP_UTF8, NULL, wszString, wcslen(wszString), NULL, 0, NULL, NULL); char* szU8 = new char[u8Len + 1]; ::WideCharToMultiByte(CP_UTF8, NULL, wszString, wcslen(wszString), szU8, u8Len, NULL, NULL); szU8[u8Len] = '\0'; string strUtf8=szU8;delete[] szU8;return strUtf8;}string CEncodeString::GetUnicodeHeader(){return "\xff\xfe";}string CEncodeString::GetUtf8Header(){return "\xef\xbb\xbf";}main(){setlocale(LC_CTYPE, ""); FILE *f=fopen("d:\\json.txt","rb");char buf[100]={0};fread(buf,1,100,f);fclose(f);CEncodeString encode;encode.LoadString(buf);cout<<encode.ToAnsi()<<endl;}
这个类会自动解析字符串的头信息，判断是否为unicode还是utf8还是ansi，然后会做相应的处理，当然字符串在类中的储存方式都是ansi的。
本文由不足之处，还望大家多多指正。