Help! How do I send extensible data in my WS-Eventing Subscribe?

Reader Nitin raises a good question: how does an app put extensible data into the Subscribe message that’s used to set up events? Example scenario: WSD ScanNitin’s question asks specifically about the WSD Scan protocol built into Vista and Servier 2008, so I’ll use that as an example.  The scan protocol defines a ScanAvailableEvent (and…

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More on attachments

Since my monologue on the IWSDAttachment object last week, it’s occured to me that there’s a much simpler way to explain which programming patterns you have to use when reading from or writing to WSDAPI attachments. Here’s a table that describes it.  To use this table, you need to determine whether you’re writing a client…

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Help! I can’t write to my attachments!

Another day, and another detour from WSDAPI 101.  Today’s article comes courtesy of WSDAPI’s attachment interfaces, which are often the subject of questions I receive from fellow developers.  In specific, I’m talking about: IWSDOutboundAttachment::Write, and to a much lesser extent, IWSDInboundAttachment::Read The problem goes like this: you’d like to code a client that sends a…

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Help! WSDAPI crashes after my service method returns!

I’m going to take a quick detour from WSDAPI 101 to comment on an issue you may have seen when developing and testing a service or client based on WSDAPI. The symptoms of this crashThis problem may arise in two scenarios: You have a service object hosted by the WSDAPI device host.  A wire message…

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