【转】各种字符编码转换

#pragma once  
#include <string>  
#include <Windows.h>  
using namespace std;  
#define SAFE_DELETE_ARRAY(p)\
 if (p != NULL)\
 {\
	delete [] p;\
	p = NULL;\
 }\

namespace utility  
{  
	string unicode_2_ansi(const wchar_t *p_in)  
	{     
		int nLen = WideCharToMultiByte(CP_OEMCP, 0, p_in, -1, NULL, 0, NULL, FALSE);  
		char *p_out = new char[nLen];  
		memset(p_out, 0, nLen);  
		WideCharToMultiByte(CP_OEMCP, 0, p_in, -1, p_out, nLen, NULL, FALSE);  
		string s_out(p_out); 
		SAFE_DELETE_ARRAY(p_out);  
		return s_out;  
	}  
	wstring ansi_2_unicode(const char *p_in)  
	{  
		int nLen = MultiByteToWideChar(CP_ACP, 0, p_in, -1, NULL, 0);  
		wchar_t *p_out = new wchar_t[nLen];  
		memset(p_out, 0, nLen);  
		MultiByteToWideChar(CP_ACP, 0, p_in, -1, p_out, nLen);  
		wstring s_out(p_out);  
		SAFE_DELETE_ARRAY(p_out);  
		return s_out;  
	}  
	string unicode_2_utf8(const wchar_t *p_in)  
	{  
		int nLen = WideCharToMultiByte(CP_UTF8, 0, p_in, -1, NULL, 0, NULL, FALSE);  
		char *p_out = new char[nLen];  
		memset(p_out, 0, nLen);  
		WideCharToMultiByte(CP_UTF8, 0, p_in, -1, p_out, nLen, NULL, FALSE);  
		string s_out(p_out);  
		SAFE_DELETE_ARRAY(p_out);  
		return s_out;  
	}  
	wstring utf8_2_unicode(const char *p_in)  
	{  
		int nLen = MultiByteToWideChar(CP_UTF8, 0, p_in, -1, NULL, 0);  
		wchar_t *p_out = new wchar_t[nLen];  
		memset(p_out, 0, nLen);  
		MultiByteToWideChar(CP_UTF8, 0, p_in, -1, p_out, nLen);  
		wstring s_out(p_out);  
		SAFE_DELETE_ARRAY(p_out);  
		return s_out;  
	}  
	string ansi_2_utf8(const char *p_in)  
	{  
		wstring str = ansi_2_unicode(p_in);  
		return unicode_2_utf8(str.c_str());  
	}  
	string wstring_2_string(wstring s_in)  
	{  
		return unicode_2_ansi(s_in.c_str());  
	}  
	wstring string_2_wstring(string s_in)  
	{  
		return ansi_2_unicode(s_in.c_str());  
	}  
}