Silverlight Async

What is the reason behind async call for SilverLig开发者_Python百科ht? You can't have a sync call when communicating with a WCF service?

You might want to read OMG, Silverlight! Asynchronous is Evil! (or, Call me back when you got it)

The bottom line is this: if Microsoft were to allow every petition-signing Tom, Dick and Harry blowhard / hotshot developer to make synchronous calls because they are too lazy and crybaby to learn how to do it better, there would DEFINITELY be a lot of very unhappy people with frozen browsers out there in SilverLand -- and guess who would get blamed? Microsoft!

Because your UI hangs while waiting for syncronous webservice calls to complete. Depending on the user's network and connectivity state, that could be a very long wait - and a very poor user experience if your UI is hung for that long