Question

I have a WCF service and consuming it in my silverlight 4 application. i have 5 async calls. how can i know that they have completed???

 void service_StochSlowCompleted(object sender, StochSlowCompletedEventArgs e)
    {
        int count = e.Result.Count / 2;
        for (int i = 0; i < count; i++)
        {
            Stoch.Add(e.Result[i]);
        }
    }

    void service_MovingAvgCompleted(object sender, MovingAvgCompletedEventArgs e)
    {
        MA = e.Result;
    }

    void service_MomentumCompleted(object sender, MomentumCompletedEventArgs e)
    {
        PMO = e.Result;
    }

    void service_RSICompleted(object sender, RSICompletedEventArgs e)
    {
        RSI = e.Result;
    }

    void service_OBVCompleted(object sender, OBVCompletedEventArgs e)
    {
        OBV = e.Result;
    }


public void Get_Data(ObservableCollection<double> high, ObservableCollection<double> low, ObservableCollection<double> open, ObservableCollection<double> close, ObservableCollection<double> volume, ObservableCollection<DateTime> date)
    {
        service.OBVAsync(0, close.Count - 1, close, volume);
        service.RSIAsync(0, close.Count - 1, close, 9);
        service.StochSlowAsync(0, close.Count - 1, high, low, close, 14, 3, 14);
        service.MomentumAsync(0, close.Count - 1, close, 10);
        service.MovingAvgAsync(0, close.Count - 1, close, 10);

        Close = close;
        Date = date;

    }
public void Predict()
    {
        //some code uses the results returned from the serivce
    }

and outside i have:

 Prediction p = new Prediction();
p.Get_Data(high, low, open, close, volume, date);
p.Predict();

So .. please how can i know?????

Answer 1

You should Add an event named Get_DataCompleted to your Prediction class.

Raise this event when all service_*Comlpeted methods have been called. To do that, you may add a call at the end of the method that decrement an int and call raises the Get_DataCompleted when the int = 0.
Set the int to 5 at the begining of Get_Data.

You may throw an InvalidOperationException when Get_Data is called and the int is > 0. (Or abort previous calls, reinitialize, …)

Call p.Predict when the Get_DataCompleted is raised.

public event EventHandler Get_DataCompleted;

private int pendingCalls;

private void OnCompleted()
{
  pendingCalls -= 1;
  if (pendingCalls == 0 && Get_DataCompleted != null)
    Get_DataCompleted(this, EventArgs.Empty);
}

void service_StochSlowCompleted(object sender, StochSlowCompletedEventArgs e)
{
  int count = e.Result.Count / 2;
  for (int i = 0; i < count; i++)
  {
    Stoch.Add(e.Result[i]);
  }
  OnCompleted();
}

void service_MovingAvgCompleted(object sender, MovingAvgCompletedEventArgs e)
{
  MA = e.Result;
  OnCompleted();
}

void service_MomentumCompleted(object sender, MomentumCompletedEventArgs e)
{
  PMO = e.Result;
  OnCompleted();
}

void service_RSICompleted(object sender, RSICompletedEventArgs e)
{
  RSI = e.Result;
  OnCompleted();
}

void service_OBVCompleted(object sender, OBVCompletedEventArgs e)
{
  OBV = e.Result;
  OnCompleted();
}


public void Get_Data(ObservableCollection<double> high, ObservableCollection<double> low, ObservableCollection<double> open, ObservableCollection<double> close, ObservableCollection<double> volume, ObservableCollection<DateTime> date)
{
  if (pendingCalls > 0)
    throw new InvalidOperationException();
  pendingCalls = 5;
  service.OBVAsync(0, close.Count - 1, close, volume);
  service.RSIAsync(0, close.Count - 1, close, 9);
  service.StochSlowAsync(0, close.Count - 1, high, low, close, 14, 3, 14);
  service.MomentumAsync(0, close.Count - 1, close, 10);
  service.MovingAvgAsync(0, close.Count - 1, close, 10);

  Close = close;
  Date = date;

}
public void Predict()
{
  //some code uses the results returned from the serivce 
} 

outside :

  Prediction p = new Prediction();
  p.Get_Data(high, low, open, close, volume, date);
  p.Get_DataCompleted += new EventHandler(p_Get_DataCompleted);

void p_Get_DataCompleted(object sender, EventArgs e)
{
  (sender as Prediction).Predict();
}