您好我正在使用visual studio c ++ 2010而我仍然不那么擅长。我正在使用wmi查询,我想在使用if之前使用if cout结果这里是代码
IEnumWbemClassObject* pEnumerator = NULL;
hres = pSvc->ExecQuery(
bstr_t("WQL"),
bstr_t("SELECT * FROM Win32_ComputerSystem"),
WBEM_FLAG_FORWARD_ONLY | WBEM_FLAG_RETURN_IMMEDIATELY,
NULL,
&pEnumerator);
if (FAILED(hres))
{
cout << "Query for CS failed."
<< " Error code = 0x"
<< hex << hres << endl;
pSvc->Release();
pLoc->Release();
CoUninitialize();
return 1; // Program has failed.
}
// Get the data from the query
IWbemClassObject *pclsObj;
ULONG uReturn = 0;
while (pEnumerator)
{
HRESULT hr = pEnumerator->Next(WBEM_INFINITE, 1,
&pclsObj, &uReturn);
if(0 == uReturn)
{
break;
}
VARIANT vtProp;
// Get the value of the Name property
hr = pclsObj->Get(L"Manufacturer", 0, &vtProp, 0, 0);
if (vtProp.bstrVal == "test") //// HERE IS THE PROB HOW TO FIX HERE?I WANT TO SAY IF THE RESULT ="WHATEVER" THEN
wcout << "\Manufacturer : " << vtProp.bstrVal << endl; // or do stuff
VariantClear(&vtProp);
pclsObj->Release();
错误是:错误C2446:&#39; ==&#39; :没有来自&#39; const char *&#39;到BSTR&#39; 我还是初学者,我不知道要解决这个问题,请帮忙!!!
答案 0 :(得分:2)
这里至少有两个问题:
BSTR看起来像一个字符串但不完全像C字符串。阅读更多here。所以你必须要小心差异。
即使vtProp.bstrVal是C字符串,您的比较也不会起作用,因为vtProp.bstrVal == "test"
会比较指针的地址而不是字符串的内容。
对于简单的比较,就像在代码中一样,解决方案是用
替换您的测试wcscmp(vtProp.bstrVal, L"test")==0