Question

I have a simple service with a single operational contract method called Sum

[OperationContact]
int sum(int i, int q);

When I am integrating the web service into a Silverlight app, adding this code into the main page:

ServiceReference1.Service1Client obj = new ServiceReference1.Service1Client();

it doesn’t call sum method. Moreover it shows:

obj.sumAsync(int i, int q)

Answer 1

Silverlight doesn’t allow creation of a sync proxy of Web Services. It uses an async service proxy model. There will be two properties for each OperationContract in Silverlight:

obj.sumAsync(int i, int q, object state)
obj.sumAsyncCompleted; // Event

You should try this:

private void CallMethod()
{    
    obj.sumAsync(2,2);
    obj.sumAsyncCompleted += (s,e) =>
        {
            if (e.Error == null)
            {
                   MessageBox.Show(e.Result.ToString());
            }
        };
}