Wide Char To Multi-Byte - windows

Question

I'm trying to convert wide char into multi-byte. It's only on yje myfile part. The rest works fine.I can't use wofstream because I am using ofstream in several places, so I am left with this.
void PrintBrowserInfo(IWebBrowser2 *pBrowser) {
BSTR bstr;
pBrowser->get_LocationURL(&bstr);
std::wstring wsURL;
wsURL = bstr;
size_t DSlashLoc = wsURL.find(L"://");
if (DSlashLoc != wsURL.npos)
{
wsURL.erase(wsURL.begin(), wsURL.begin() + DSlashLoc + 3);
}
DSlashLoc = wsURL.find(L"www.");
if (DSlashLoc == 0)
{
wsURL.erase(wsURL.begin(), wsURL.begin() + 4);
}
DSlashLoc = wsURL.find(L"/");
if (DSlashLoc != wsURL.npos)
{
wsURL.erase(DSlashLoc);
}
wprintf(L"\n URL: %s\n\n", wsURL.c_str());
char LogURL = WideCharToMultiByte( CP_ACP, WC_COMPOSITECHECK, wsURL.c_str(), -1, NULL, 0, NULL, NULL);
myfile << "\n URL:" << LogURL;
SysFreeString(bstr);
}
void EnumExplorers() {
CoInitialize(NULL);
SHDocVw::IShellWindowsPtr spSHWinds;
IDispatchPtr spDisp;
if (spSHWinds.CreateInstance(__uuidof(SHDocVw::ShellWindows)) == S_OK) {
long nCount = spSHWinds->GetCount();
for (long i = 0; i < nCount; i++) {
_variant_t va(i, VT_I4);
spDisp = spSHWinds->Item(va);
SHDocVw::IWebBrowser2Ptr spBrowser(spDisp);
if (spBrowser != NULL) {
PrintBrowserInfo((IWebBrowser2 *)spBrowser.GetInterfacePtr());
spBrowser.Release();
}
}
} else {
puts("Shell windows failed to initialise");
}
}

Answer 1

You're using WideCharToMultiByte wrong. You need to pass it a string buffer to receive the converted string. Using NULL and 0 as parameters as you have done will return the required size of the result string.
int length = WideCharToMultiByte (CP_ACP, WC_COMPOSITECHECK, wsURL.c_str(), -1, NULL, 0, NULL, NULL);
std::string LogURL(length+1, 0);
int result = WideCharToMultiByte (CP_ACP, WC_COMPOSITECHECK, wsURL.c_str(), -1, &LogURL[0], length+1, NULL, NULL);
You should check result for a non-zero value to make sure the function worked correctly.