c++编写字符串编码类

废话不多说，上代码：

[cpp]
#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。

补充：软件开发 , C++ ,