// This example shows how subscribe to changes of multiple items and display the value of the item with each change, // using a callback method specified using lambda expression. using System.Diagnostics; using OpcLabs.EasyOpc.DataAccess; using System; using System.Threading; namespace DocExamples { namespace _EasyDAClient { class SubscribeItem { public static void CallbackLambda() { // Instantiate the client object var easyDAClient = new EasyDAClient(); Console.WriteLine("Subscribing..."); // The callback is a lambda expression the displays the value easyDAClient.SubscribeItem("", "OPCLabs.KitServer.2", "Simulation.Random", 1000, (sender, eventArgs) => { Debug.Assert(eventArgs != null); if (eventArgs.Exception != null) Console.WriteLine(eventArgs.Exception.ToString()); else { Debug.Assert(eventArgs.Vtq != null); Console.WriteLine(eventArgs.Vtq.ToString()); } }); Console.WriteLine("Processing item changed events for 10 seconds..."); Thread.Sleep(10 * 1000); Console.WriteLine("Unsubscribing..."); easyDAClient.UnsubscribeAllItems(); Console.WriteLine("Waiting for 2 seconds..."); Thread.Sleep(2 * 1000); } } } }

// This example shows how subscribe to changes of multiple items and display the value of the item with each change. using JetBrains.Annotations; using OpcLabs.EasyOpc.DataAccess; using OpcLabs.EasyOpc.DataAccess.OperationModel; using System; using System.Threading; namespace DocExamples { namespace _EasyDAClient { partial class SubscribeMultipleItems { public static void Main() { using (var easyDAClient = new EasyDAClient()) { easyDAClient.ItemChanged += easyDAClient_ItemChanged; easyDAClient.SubscribeMultipleItems( new[] { new DAItemGroupArguments("", "OPCLabs.KitServer.2", "Simulation.Random", 1000, null), new DAItemGroupArguments("", "OPCLabs.KitServer.2", "Trends.Ramp (1 min)", 1000, null), new DAItemGroupArguments("", "OPCLabs.KitServer.2", "Trends.Sine (1 min)", 1000, null), new DAItemGroupArguments("", "OPCLabs.KitServer.2", "Simulation.Register_I4", 1000, null) }); Console.WriteLine("Processing item changed events for 1 minute..."); Thread.Sleep(60 * 1000); } } // Item changed event handler static void easyDAClient_ItemChanged([NotNull] object sender, [NotNull] EasyDAItemChangedEventArgs e) { Console.WriteLine("{0}: {1}", e.Arguments.ItemDescriptor.ItemId, e.Vtq); } } } }