async callback in Silverlight client RRS feed

  • Question

  • Hello,

    In the Silverlight client screen _Created method, I want to hit a web api to perform some data operations on the server (i.e. commanding).  No problem there.  Question: Once the operations are complete on the server, how can I get a callback to refresh the SL client screen.  I want this to happen asynchronously so that I don't block the ui while the operation is underway.  TIA

    Wednesday, November 5, 2014 3:24 PM

All replies

  • Hi!

    Didn't play with this myself, but recently was searching some things on Paul van Bladel's blog and there you have some examples of async stuff.. 

    check http://blog.pragmaswitch.com/?tag=async , maybe it helps..


    Nobody expects the Spanish Inquisition! (M.P.F.C.)

    Wednesday, November 5, 2014 3:33 PM
  • Kivito,

    Thanks for that.  I will check it out.

    Wednesday, November 5, 2014 4:07 PM
  • The Async section of Paul Van Bladel's blog is very helpful.  However, I am still not sure how to get a call back from web api.  Does anyone know how to accomplish this in the Sliverlight client?  Thanks.
    Thursday, November 6, 2014 1:30 PM
  • Hi Hessc,

    >>Question: Once the operations are complete on the server, how can I get a callback to refresh the SL client screen.

    API support for refreshing data on lists and screens in the runtime app, please check whether it helps you.

    • Asynchronously loads the first page of items into this collection and           
      returns a promise that will be fulfilled when the first page is loaded.            
    • Updates the entity with values from the data source if the entity           
      is not changed.

    See: New API For Refreshing Data in LightSwitch in Visual Studio 2013 

    Please let me know if there is anything that I can do to help.

    Best regards,


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    Wednesday, November 19, 2014 7:29 AM
  • See: https://code.msdn.microsoft.com/vstudio/Simple-web-api-based-file-5e0c5844/sourcecode?fileId=96705&pathId=1513641315


    paul van bladel ==independent enterprise application architect== http://blog.pragmaswitch.com

    Wednesday, November 19, 2014 10:46 AM
  • Thanks Paul.  Lots of great stuff in that sample.
    Friday, November 21, 2014 6:17 AM
  • Could you find specifically what you were looking for?

    paul van bladel ==independent enterprise application architect== http://blog.pragmaswitch.com

    Friday, November 21, 2014 8:32 AM
  • Paul,

    I did not see a callback from asynchronous code in the sample.  It may be there but I have not gone through all of it yet.  Nevertheless, there are lots of other things in there that will be helpful.  What I am trying to do is perform some operations after LS sends emails from an async method. 

    // simplified version private static async Task SendAsync(MailMessage message) { using (SmtpClient client = new SmtpClient("somemailhub.com", 25)) { client.UseDefaultCredentials = true; try { await client.SendMailAsync(message); // how to get the callback?

    // do stuff here } catch (Exception) // Make this specific { throw; } } }

    This code works fine, I just want to do some logging so I can record whether or not the message was successfully delivered and that sort of thing.

    • Edited by Hessc Friday, November 21, 2014 9:00 PM
    Friday, November 21, 2014 8:58 PM
  • I just realized that the async callback on the server in my last post is not the same issue I originally posted about -- sorry for that.  In the OP, I am looking for a way to await a task initiated on the client.  I am still in need of that.  In my last post, I am looking for the way to get the callback so I can do something with the results. 
    Friday, November 21, 2014 9:12 PM