Async Web Service Timout

When using SOAP-based web services (in this case with MonoDevelop / MonoTouch) I found I had to rely on the asynchronous proxy web methods to keep my UI responsive. Pretty common, right? Unfortunately, the asynchronous web methods seem to ignore the TimeOut property on the service. Without a timeout my users could be left waiting indefinitely on an unresponsive server. Not acceptable.

To get around this issue I came up with a way to cancel an asynchronous web method request after a set period of time using a Timer object. Maybe it can help others in a similar predicament? Here's some sample code:

protected void GetServiceData()
{
 //Indicates that network activity is going on
 UIApplication.SharedApplication.NetworkActivityIndicatorVisible = true;
    
 //Make the async call
 using (MyService service = new MyService())
 {  
  //Timer is set to go off one time after 15 seconds
  Timer serviceTimer = new Timer(15000);
  serviceTimer.AutoReset = false;
  serviceTimer.Elapsed += delegate(object source, ElapsedEventArgs e) {
  service.Abort();
   throw new WebException("Timeout expired!"); 
  };
  serviceTimer.Enabled = true;     

  //Call the desired web method
  service.WebMethodCompleted += ServiceWebMethodCompleted;  
  service.WebMethodAsync(serviceTimer);
 }
}

//The async callback method
protected void ServiceWebMethodCompleted(object sender, WebMethodCompletedEventArgs e)
{
 using (NSAutoreleasePool pool = new NSAutoreleasePool())
 {
  //Disable the timer that would abort this call with an exception 
  //if the call to this web method took too long
  Timer serviceTimer = e.UserState as Timer;
  if (serviceTimer != null)
  {
   serviceTimer.Enabled = false;
   serviceTimer.Dispose();
  }
    
  if (e.Error != null)
  {
   if (e.Error is WebException)
   {
    //An error due to a timeout happened - handle it here      
   }
   else
   {
    //Handle all other errors here
   }
  }
  else
  {
   //Async call successful - do something cool with e.Result    
  }
 
  //Indicates network activity has finished
  this.InvokeOnMainThread(delegate() {
   UIApplication.SharedApplication.NetworkActivityIndicatorVisible = false;
  });
 }   
}