class OrderServiceImpl : IOrderService
{
    string orderId;
    public WorkflowInstance instanceId;

    // Called by the workflow to pass an order id
    public void CreateOrder(string Id)
    {
        Console.WriteLine("\nPurchase Order Created in System");
        orderId = Id;
    }

    // Called by the host to approve an order
    public void ApproveOrder()
    {
        EventHandler<OrderEventArgs> orderApproved = this.OrderApproved;
        if (orderApproved != null)
            orderApproved(null, new OrderEventArgs(instanceId.InstanceId, orderId));
    }

    // Called by the host to reject an order
    public void RejectOrder()
    {
        EventHandler<OrderEventArgs> orderRejected = this.OrderRejected;
        if (orderRejected != null)
            orderRejected(null, new OrderEventArgs(instanceId.InstanceId, orderId));
    }

    // Events that handled within a workflow by HandleExternalEventActivity activities
    public event EventHandler<OrderEventArgs> OrderApproved;
    public event EventHandler<OrderEventArgs> OrderRejected;
}