why nResult != nConvertedLen,when use CComBSTR;
- by hxboxy
CComBSTR wsData = (char*)pvData;
when constuct CComBSTR,call A2WBSTR,but sometimes nResult != nConvertedLen,just 1/20. why?
inline BSTR A2WBSTR(_In_opt_ LPCSTR lp, int nLen = -1)
{
if (lp == NULL || nLen == 0)
return NULL;
USES_CONVERSION_EX;
BSTR str = NULL;
#pragma warning(push)
#pragma warning(disable: 6385)
int nConvertedLen = MultiByteToWideChar(_acp_ex, 0, lp,
nLen, NULL, NULL);
#pragma warning(pop)
int nAllocLen = nConvertedLen;
if (nLen == -1)
nAllocLen -= 1; // Don't allocate terminating '\0'
str = ::SysAllocStringLen(NULL, nAllocLen);
if (str != NULL)
{
int nResult;
nResult = MultiByteToWideChar(_acp_ex, 0, lp, nLen, str, nConvertedLen);
ATLASSERT(nResult == nConvertedLen);
if(nResult != nConvertedLen)
{
SysFreeString(str);
return NULL;
}
}
return str;
}
