private void AppInstalledMethod(SPRemoteEventProperties _properties)
        {
            using (ClientContext clientContext = TokenHelper.CreateAppEventClientContext(_properties, false))
            {
                if (clientContext != null)
                {
                    Web web = clientContext.Web;
                    var list = web.Lists.GetByTitle("MyDoc3");
                    clientContext.Load(web);
                    clientContext.Load(list);
                    clientContext.Load(list.EventReceivers);
                    clientContext.ExecuteQuery();

                    EventReceiverDefinitionCreationInformation receiver = new EventReceiverDefinitionCreationInformation();
                    receiver.EventType = EventReceiverType.ItemAdding;
                    OperationContext op = OperationContext.Current;
                    Message msg = op.RequestContext.RequestMessage;
                    receiver.ReceiverUrl = msg.Headers.To.ToString();
                    receiver.ReceiverName = "ItemAddingEvent";
                    receiver.Synchronization = EventReceiverSynchronization.Synchronous;
                    receiver.SequenceNumber = 5000;
                    list.EventReceivers.Add(receiver);

                    EventReceiverDefinitionCreationInformation receiverUpdate = new EventReceiverDefinitionCreationInformation();
                    receiverUpdate.EventType = EventReceiverType.ItemUpdating;
                    //op = OperationContext.Current;
                    //msg = op.RequestContext.RequestMessage;
                    receiverUpdate.ReceiverUrl = msg.Headers.To.ToString();
                    receiverUpdate.ReceiverName = "ItemUpdatingEvent";
                    receiverUpdate.Synchronization = EventReceiverSynchronization.Synchronous;
                    receiverUpdate.SequenceNumber = 5000;
                    list.EventReceivers.Add(receiverUpdate);

                    clientContext.ExecuteQuery();
                }
            }
        }


public SPRemoteEventResult ProcessEvent(SPRemoteEventProperties properties)
        {
            SPRemoteEventResult result = new SPRemoteEventResult();
            switch (properties.EventType)
            {

                case SPRemoteEventType.AppInstalled:
                    AppInstalledMethod(properties);
                    break;
                case SPRemoteEventType.AppUpgraded:
                    AppUpgradedMethod(properties);
                    break;
                case SPRemoteEventType.ItemAdding:
                    ItemAddingMethod(properties);
                    break;
                case SPRemoteEventType.ItemUpdating:
                    ItemUpdatingMethod(properties);
                    break;
                case SPRemoteEventType.WebAdding:
                    // you can implement webaddding event
                    break;
                case SPRemoteEventType.WebDeleting:
                //you can implemet web deleting event if needed.
                default:
                    break;
            }
            return result;



        }

        private void ItemUpdatingMethod(SPRemoteEventProperties _properties)
        {
            using (ClientContext clientContext = TokenHelper.CreateRemoteEventReceiverClientContext(_properties))
            {
                if (clientContext != null)
                {
                    var afterproperties = _properties.ItemEventProperties.AfterProperties;
                }
            }
        }