How overriding correctly GetDisplayName (OPM) ?

[maisoui]

Hi,

I implemented OPM wrapper for my custom entity and I overrided the method GetDisplayName to specify custom properties names and a custom display name like this:

STDMETHODIMP CCustomWrapper::GetDisplayName(DISPID dispId, BSTR * propName)
{
	HRESULT hr = S_OK;

	switch(dispId)
	{	
	case DISPID_...:
		*propName = ::SysAllocString(_T("My property"));
		break;

	case DISPID_DISPLAYNAME:
		*propName = ::SysAllocString(_T("MyCustomEntity"));
		break;

	default:
		hr = IOPMPropertyExtensionImpl<CCustomWrapper>::GetDisplayName(dispId, propName);
		assert(hr == S_OK);
	}

	return hr;
}

The problem is that the call to IOPMPropertyExtensionImpl<CCustomWrapper>::GetDisplayName(dispId, propName); always returns E_FAIL. The result is that the name of each common properties of AcDbEntities is not correct. See the images below:

What did I do wrong? In the ObjectARX samples, no call to the parent IOPMPropertyExtensionImpl is made...

Regards,

Jonathan

[owenwengerd · Accepted solution]

As far as I know, the only solution is to create a separate wrapper instance (I create one of the base class entity type), then call it's GetDisplayName member function.

CComQIPtr<IOPMPropertyExtension> OPEHelper;
OPEHelper.CoCreateInstance( CLSID_AcadLine );

if (dispID >= 0x100 && OPEHelper)
{
	hr = OPEHelper->GetDisplayName(dispID, propName);
	if (SUCCEEDED(hr))
		return S_OK;
}
hr = __super::GetDisplayName(dispID, propName);

[maisoui]

Hi Owen,

Thank you for your answer. Your solution works.

Maybe there is a easier (lighter) solution?

Regards,

Jonathan

[KIMHENGHOR98]

Could you share me your project example?

[KIMHENGHOR98]

I added a COM wrapper for my entity but getdisplayname() method never get called