字符串在各种编码下的转换

char*   ——》   CStirng

void CharToCString(CString& str, char *chr)
{
    CString pWideChar=_T("");
    //  计算char *数组大小，以字节为单位，一个汉字占两个字节
    int charLen = strlen(chr);    
    //计算多字节字符的大小，按字符计算。
    int len = MultiByteToWideChar(CP_ACP,0,chr,charLen,NULL,0);    
    //为宽字节字符数组申请空间，数组大小为按字节计算的多字节字符大小
    TCHAR *buf = new TCHAR[len + 1];    
    //多字节编码转换成宽字节编码
    MultiByteToWideChar(CP_ACP,0,chr,charLen,buf,len);    
    buf[len] = ''; //添加字符串结尾，注意不是len+1    
    //将TCHAR数组转换为CString
    pWideChar.Format(L"%s",buf);
    //删除缓冲区
    delete []buf;
    str=pWideChar;
}

CString  ——》  char*

void CStringToChar(CString str, char**chr)
{
    *chr = (char*)malloc(wcslen(str) * 2);
    ::WideCharToMultiByte(CP_ACP,0,str,-1,*chr,wcslen(str) * 2,NULL,NULL);
}

Utf-8    ——》  Unicode

void U8ToUnicode(char *Utf8, CString &str)
{
    DWORD dwUnicodeLen;
    TCHAR* pwText;
    dwUnicodeLen = MultiByteToWideChar(CP_UTF8, 0, Utf8, -1, NULL,0);
    pwText = new TCHAR[dwUnicodeLen+1];
    memset(pwText, 0, dwUnicodeLen+1);
    MultiByteToWideChar(CP_UTF8, 0, Utf8, -1, pwText, dwUnicodeLen);
    str.Format( _T("%s"), pwText );
    delete []pwText;
}

Unicode  ——》 Utf-8

char* UnicodeToU8(const CString &src)
{
    int len;  
    len = WideCharToMultiByte(CP_UTF8, 0, (LPCWSTR)src, -1, NULL, 0, NULL, NULL);  
    char *szUtf8 = new char[len + 1];
    memset(szUtf8, 0, len + 1);
    WideCharToMultiByte (CP_UTF8, 0, (LPCWSTR)src, -1, szUtf8, len, NULL,NULL);
    return szUtf8;
}