QueryInterface执行失败,我如何知道失败的原因呢?
// Access IAdvancedMath
IAdvancedMath* pAdvancedMath = 0;
hr = pMath->QueryInterface( IID_IAdvancedMath,
(void**) &pAdvancedMath );
if ( SUCCEEDED( hr ))
{
pAdvancedMath->Factorial( 12, &lResult );
cout << "12! = " << lResult << endl;
pAdvancedMath->Fibonacci( 12, &lResult );
cout << "The Fibonacci of 12 = " << lResult << endl;
}