ISupportErrorInfo::InterfaceSupportsErrorInfo

HRESULT InterfaceSupportsErrorInfo(

REFIID  riid  
);
 

Indicates whether or not an interface supports the IErrorInfo interface.

Parameter

riid

Pointer to an interface identifier (IID).

Return Value

The return value obtained from the returned HRESULT is one of the following:

Comments

Objects that support the IErrorInfo interface must also implement this interface.

Programs that receive an error return value should call QueryInterface to get a pointer to the ISupportErrorInfo interface, and then call InterfaceSupportsErrorInfo with the riid of the interface that returned the return value. If InterfaceSupportsErrorInfo returns S_FALSE, then the error object does not represent an error returned from the caller, but from somewhere else. In this case, the error object can be considered incorrect and should be discarded.

If ISupportErrorInfo returns S_OK, use the GetErrorInfo function to get a pointer to the error object.

Example

The following example implements the ISupportErrorInfo for the Lines sample. The IErrorInfo implementation also supports the AddRef, Release, and QueryInterface members inherited from the IUnknown interface.

CSupportErrorInfo::CSupportErrorInfo(IUnknown FAR* punkObject, REFIID riid)
{
    m_punkObject = punkObject;
    m_iid = riid;
}


STDMETHODIMP
CSupportErrorInfo::QueryInterface(REFIID iid, void FAR* FAR* ppv)
{
    return m_punkObject->QueryInterface(iid, ppv);
}


STDMETHODIMP_(ULONG)
CSupportErrorInfo::AddRef(void)
{
    return m_punkObject->AddRef();
}

STDMETHODIMP_(ULONG)
CSupportErrorInfo::Release(void)
{
    return m_punkObject->Release();
}

STDMETHODIMP
CSupportErrorInfo::InterfaceSupportsErrorInfo(REFIID riid)
{
    return (riid == m_iid) ? NOERROR : ResultFromScode(S_FALSE);
}