// This example shows how to subscribe to event notifications and display each incoming event
// using a callback method that is provided as lambda expression.
using System;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.AddressSpace.Standard;
namespace UADocExamples.AlarmsAndConditions
{
partial class SubscribeEvent
{
public static void CallbackLambda()
{
UAEndpointDescriptor endpointDescriptor =
"opc.tcp://opcua.demo-this.com:62544/Quickstarts/AlarmConditionServer";
// Instantiate the client object
var client = new EasyUAClient();
Console.WriteLine("Subscribing...");
// The callback is a lambda expression the displays the event
client.SubscribeEvent(
endpointDescriptor,
UAObjectIds.Server,
1000,
(sender, eventArgs) => Console.WriteLine(eventArgs));
// Remark: Production code needs to check eventArgs.Exception before accessing eventArgs.EventData.
Console.WriteLine("Processing event notifications for 30 seconds...");
System.Threading.Thread.Sleep(30 * 1000);
Console.WriteLine("Unsubscribing...");
client.UnsubscribeAllMonitoredItems();
Console.WriteLine("Waiting for 2 seconds...");
System.Threading.Thread.Sleep(2 * 1000);
}
}
}
# This example shows how to subscribe to event notifications and display each incoming event
# using a callback method that is provided as lambda expression.
# The QuickOPC package is needed. Install it using "pip install opclabs_quickopc".
import opclabs_quickopc
import time
# Import .NET namespaces.
from OpcLabs.EasyOpc.UA import *
from OpcLabs.EasyOpc.UA.AddressSpace.Standard import *
# Define which server we will work with.
endpointDescriptor = UAEndpointDescriptor('opc.tcp://opcua.demo-this.com:62544/Quickstarts/AlarmConditionServer')
# Instantiate the client object.
client = EasyUAClient()
print('Subscribing...')
# The callback is a lambda expression the displays the event.
IEasyUAClientExtension.SubscribeEvent(
client,
endpointDescriptor,
UANodeDescriptor(UAObjectIds.Server),
1000,
EasyUAEventNotificationEventHandler(lambda server, eventArgs: print(eventArgs)))
# Remark: Production code needs to check eventArgs.Exception before accessing eventArgs.EventData.
print('Processing event notifications for 30 seconds...')
time.sleep(30)
print('Unsubscribing...')
client.UnsubscribeAllMonitoredItems()
print('Waiting for 2 seconds...')
time.sleep(2)
print('Finished.')
' This example shows how to subscribe to event notifications and display each incoming event
' using a callback method that is provided as lambda expression.
Imports OpcLabs.EasyOpc.UA
Imports OpcLabs.EasyOpc.UA.AddressSpace.Standard
Namespace AlarmsAndConditions
Partial Friend Class SubscribeEvent
Public Shared Sub CallbackLambda()
' Instantiate the client object
Dim client = New EasyUAClient()
Console.WriteLine("Subscribing...")
' The callback is a lambda expression the displays the event
client.SubscribeEvent( _
"opc.tcp://opcua.demo-this.com:62544/Quickstarts/AlarmConditionServer", _
UAObjectIds.Server, _
1000, _
Sub(sender, eventArgs) Console.WriteLine(eventArgs))
' Remark: Production code would check e.Exception before accessing e.EventData.
Console.WriteLine("Processing event notifications for 10 seconds...")
Threading.Thread.Sleep(10 * 1000)
Console.WriteLine("Unsubscribing...")
client.UnsubscribeAllMonitoredItems()
Console.WriteLine("Waiting for 2 seconds...")
Threading.Thread.Sleep(2 * 1000)
End Sub
End Class
End Namespace
