public double GetVolume()
{
EventHandler <GetVolumeCompletedEventArgs> callback = null;
var tcs = new TaskCompletionSource <double>();
callback = (sender, args) =>
{
RequestState state = PerformOperation(() => { tcs.SetResult(args.Result); });
if (state != RequestState.Correct)
{
tcs.SetResult(0);
}
_systemServiceCient.GetVolumeCompleted -= callback;
};
_systemServiceCient.GetVolumeCompleted += callback;
_systemServiceCient.GetVolumeAsync();
return(tcs.Task.Result);
}
