Question

I’m working with a web service I didn’t write myself (and so cannot edit). I have this code:

public void GetData()
{
    try
    {
        TelemeterServiceClient client = new TelemeterServiceClient();
        RetrieveUsageRequestType request = new RetrieveUsageRequestType { UserId = Username, Password = Password };
        RetrieveUsageResponseType response = client.retrieveUsage(request);
        Result = response.Item;

        Callback(null);
    }
    catch (Exception e)
    {
       Result = null;
       Callback(e);
    }
}

This works fine in a WPF project. However, I’m now working with a Windows Phone project, which uses Silverlight. In this project, the retrieveUsage()-method cannot be found.

Apparently Silverlight only supports asynchronous calls to web services. And indeed, there is a retrieveUsageAsync()-method present.

But how do I use this method and get the result back? Can someone provide me a simple example of how to use async calls?

Thanks

Answer 1

here’s an example:

    Dim proxy = new TelemeterServiceClient()

    AddHandler proxy.retrieveUsageCompleted, Sub(o, e)
                                                          action(o, e)
                                                      End Sub

    Using New OperationContextScope(proxy.InnerChannel)
        Dim request = New retrieveUsageRequest
        proxy.retrieveUsageAsync(request)
    End Using

Think it’s translated to c# like this:

    var proxy = new TelemeterServiceClient();

    proxy.retrieveUsageCompleted += MethodYouImplementWhenAsyncIsComplete;
    //or proxy.retrieveUsageCompleted += (s, e) => { do something };

    using (new OperationContextScope(proxy.InnerChannel))
    {
        var request = New retrieveUsageRequest();
        proxy.retrieveUsageAsync(request);
    }

In the line with action , action stands for a delegate or action where you handle your async result

Let me know if you have troubles translating this into c# then i’ll change it 😉