OPC Labs QuickOPC 2020.3

The SubscribeMultipleDataChanges extension method seems to be documented on the link you sent, but it doesn't recognize it in my program. Below is the error I receive with the directives I am using. Can you provide an example for passing a DataChangeCallback in the EasyUAMonitoredArguments.

using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.OperationModel;

"Error CS1061 'EasyUAClient' does not contain a definition for 'SubscribeMultipleDataChanges' and no accessible extension method 'SubscribeMultipleDataChanges' accepting a first argument of type 'EasyUAClient' could be found (are you missing a using directive or an assembly reference?)

I am switching from OPC DA to OPC UA. In OPC DA the SubscribeMultipleItems method comes with a callback argument. For OPC UA the SubscribeMultipleMonitoredItems method does not come with a callback argument. How can I implement a callback for SubscribeMultipleMonitoredItems in OPC UA?

OPC DA Example:

 

easyDAClient1.SubscribeMultipleItems(items.ToArray(), (_, e) => {

          if (e.Vtq != null && e.Vtq.HasValue)

          {

            String tag = e.Arguments.ItemDescriptor.ItemId.ToString();

            object value = e.Vtq.Value;

            itemChanged(tag, value);

          }

        });

 

 

OPC UA Example:

 

easyUAClient1.SubscribeMultipleMonitoredItems(items.ToArray());