转载 ANSI、Unicode、UTF8相互转化的函数

http://stdsoft.blogbus.com/logs/56468290.html

static wstring ANSI2Unicode(const string & strin)
{
wstring strout;

// 预计算所需空间大小（已包含结束字符）,单位wchar_t
int dwNum = MultiByteToWideChar (CP_ACP, 0,strin.c_str(), -1, 0 , 0);
wchar_t * pBuffer = new wchar_t[dwNum];
if (!pBuffer)
{
return strout;
}
memset(pBuffer,0,(dwNum)*sizeof(wchar_t));

if(MultiByteToWideChar(CP_ACP, 0, strin.c_str(),-1,pBuffer,dwNum) >= 0)
{
strout = pBuffer;
}

delete[] pBuffer;
return strout;
}

static string Unicode2UTF8(const wstring & strin)
{
string strout;

//测试所需存储空间大小（已包含结束字符）,单位char
int dwNum = WideCharToMultiByte(CP_UTF8,0,strin.c_str(),-1,0,0,0,0);
char* pBuffer = new char[dwNum];
if (!pBuffer)
{
return strout;
}
memset(pBuffer,0,dwNum);

if(WideCharToMultiByte(CP_UTF8,0,strin.c_str(),-1,pBuffer,dwNum,0,0) >= 0)
{
strout = pBuffer;
}

delete[] pBuffer;
return strout;
}

static string ANSI2UTF8(const string & strin)
{
return Unicode2UTF8(ANSI2Unicode(strin));
}

static string Unicode2ANSI(const wstring & strin)
{
string strout;

//测试所需存储空间大小（已包含结束字符）,单位char
int dwNum = WideCharToMultiByte(CP_ACP,0,strin.c_str(),-1,0,0,0,0);
char* pBuffer = new char[dwNum];
if (!pBuffer)
{
return strout;
}
memset(pBuffer,0,dwNum);

BOOL use_def_char = FALSE;
if(WideCharToMultiByte(CP_ACP,0,strin.c_str(),-1,pBuffer,dwNum,"?",&use_def_char) >= 0)
{
strout = pBuffer;
}

delete[] pBuffer;
return strout;
}

static wstring UTF82Unicode(const string & strin)
{
wstring strout;

// 预计算所需空间大小（已包含结束字符）,单位wchar_t
int dwNum = MultiByteToWideChar (CP_UTF8, 0,strin.c_str(), -1, 0 , 0);
wchar_t* pBuffer = new wchar_t[dwNum];
if (!pBuffer)
{
return strout;
}
memset(pBuffer,0,dwNum*sizeof(wchar_t));

if(MultiByteToWideChar(CP_UTF8,0,strin.c_str(),-1,pBuffer,dwNum) >= 0)
{
strout = pBuffer;
}

delete[] pBuffer;
return strout;
}

static string UTF82ANSI(const string & strin)
{
return Unicode2ANSI(UTF82Unicode(strin));
}