dotnet interop: Could someone take a look at the docs for this method?

http://windowssdk.msdn.microsoft.com/en-us/library/system.runtime.interopservices.comtypes.irunningobjecttable.register.aspx

In particular, I'm interested in the return value. The docs say it is an
HRESULT. However, I sincerely doubt this. If I'm not mistaken, what it is
actually returning is the cookie needed to do the
IRunningObjectTable.Revoke.

When you think about it, if there were an error, wouldn't you expect an
exception rather than an HRESULT?

However, I'm not 100% certain, and a double-check would be appreciated.

Hi,

It's a COM trick :) A _physical_ return value of the Register method *is* an
HRESULT. Here's the raw definition:

HRESULT Register(DWORD grfFlags, IUnknown * punkObject, IMoniker *
pmkObjectName, DWORD * pdwRegister);

As you can see, the cookie is physically the last output parameter.

However, in the .NET world, the Interop layer makes things simplier for you.
It hides the HRESULT and pretends that the cookie is *the* return value.
Should the returned HRESULT indicate failure, the Interop layer throws an
exception that, in particular, contains the actual HRESULT value.

Still with me? :) Feel free to follow up, I know it's not a straightforward
topic.

--
Regards,
Dmytro Lapshyn [MVP]
http://blogs.vbcity.com/DmytroL

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