WIN32字符串轉換

用到的主要函數是WideCharToMultiByte，在這個函數中主要的是第一個參數，這個參數的具體說明參照msdn。下面給幾個字符串轉化的例子：

1、將LPCWSTR轉化成string類型

BOOL WCharToMByte(LPCWSTR lpcwszStr, string &str)
{
DWORD dwMinSize = 0;
LPSTR lpszStr = NULL;
dwMinSize = WideCharToMultiByte(CP_ACP, NULL, lpcwszStr, -1, NULL, 0, NULL, FALSE);
if (0 == dwMinSize)
{
return FALSE;
}
lpszStr = new char[dwMinSize];
WideCharToMultiByte(CP_ACP, NULL, lpcwszStr, -1, lpszStr, dwMinSize, NULL, FALSE);
str = lpszStr;
delete[] lpszStr;
return TRUE;
}

這個函數的作用是將TCHAR類型的字符串轉化成ANSI類型的字符串。

2、將ANSI類型的字符串轉化成UTF16編碼形式的字符串

std::wstring ANSI_2_UTF16(const string& strANSI)
{
int nUnicodeLength = ::MultiByteToWideChar(CP_ACP, 0, strANSI.c_str(), -1, NULL, 0);
wstring strUTF16(nUnicodeLength, _T(' '));
int nRet = ::MultiByteToWideChar(CP_ACP, 0, strANSI.c_str(), -1, &strUTF16[0], nUnicodeLength);
ASSERT(0 != nRet);
return strUTF16;
}

這個函數就是將1中轉化成的ANSI的字符串轉化成UTF16編碼形式的字符串。

3、將ANSI字符串轉化成UTF8編碼形式的字符串

char* char_2_UTF8(char* str)
{
int nLen = MultiByteToWideChar(CP_ACP, 0, str, -1, NULL, 0);
if (nLen == 0)
return "";
WCHAR *pwszBuffer = new WCHAR[nLen];
nLen = MultiByteToWideChar(CP_ACP, 0, str, -1, pwszBuffer, nLen);
if (nLen == 0)
return "";
nLen = WideCharToMultiByte(CP_UTF8, 0, pwszBuffer, -1, NULL, 0, NULL, NULL);
if (nLen == 0)
return "";
char *pszBuffer = new char[nLen];
nLen = WideCharToMultiByte(CP_UTF8, 0, pwszBuffer, -1, pszBuffer, nLen, NULL, NULL);
if (nLen == 0)
return "";
nLen = strlen(pszBuffer) + 1;
NPUTF8 * strUTF8 = static_cast<NPUTF8 *>(NPN_MemAlloc(nLen));
memset(strUTF8, 0, nLen);
strncpy(strUTF8, pszBuffer, nLen);
return strUTF8;
}

4、將string轉化成WCHAR類型字符串

std::wstring s2ws(const std::string& s) 
{ 
int len; 
int slength = (int)s.length() + 1; 
len = MultiByteToWideChar(CP_ACP, 0, s.c_str(), slength, 0, 0);  
wchar_t* buf = new wchar_t[len]; 
MultiByteToWideChar(CP_ACP, 0, s.c_str(), slength, buf, len); 
std::wstring r(buf); 
delete[] buf; 
return r; 
}