OPC Studio User's Guide and Reference
EasyUASubscribeDataSetFieldArguments Constructor(EasyUADataSetFieldMessageEventHandler,Object,UAPubSubConnectionDescriptor,UASubscribeDataSetFilter,UADataSetMetaData,UADataSetFieldDescriptor)



OpcLabs.EasyOpcUA Assembly > OpcLabs.EasyOpc.UA.PubSub.OperationModel Namespace > EasyUASubscribeDataSetFieldArguments Class > EasyUASubscribeDataSetFieldArguments Constructor : EasyUASubscribeDataSetFieldArguments Constructor(EasyUADataSetFieldMessageEventHandler,Object,UAPubSubConnectionDescriptor,UASubscribeDataSetFilter,UADataSetMetaData,UADataSetFieldDescriptor)
A callback method to be invoked for each time a dataset field is received.

The value of this parameter cannot be null (Nothing in Visual Basic).

The state object (can be any value supplied by your code); available in event notifications.

The value of this parameter can be null (Nothing in Visual Basic).

Descriptor for a PubSub connection (using physical parameters, or logical name).

Because the OpcLabs.EasyOpc.UA.PubSub.UAPubSubConnectionDescriptor has an implicit conversion from OpcLabs.BaseLib.Networking.ResourceAddress and System.String, in languages that support implicit conversion operators (such as C# or VB.NET), you can simply use a OpcLabs.BaseLib.Networking.ResourceAddress object, or a string (the so-called resource description string, usually a resource URL) in place of this parameter, and the corresponding OPC UA PubSub connection descriptor will be constructed automatically. When the implicit conversion operators are not supported (such as with Python.NET), you can use the FromResourceAddress or FromString static method instead.

Also, because the OpcLabs.EasyOpc.UA.PubSub.Configuration.UAPubSubConnectionElement has an implicit conversion to OpcLabs.EasyOpc.UA.PubSub.UAPubSubConnectionDescriptor, in languages that support implicit conversion operators (such as C# or VB.NET), you can simply use a OpcLabs.EasyOpc.UA.PubSub.Configuration.UAPubSubConnectionElement (from PubSub configuration) in place of this parameter, and the corresponding OPC UA PubSub connection descriptor will be constructed automatically. When the implicit conversion operators are not supported (such as with Python.NET), you can convert a OpcLabs.EasyOpc.UA.PubSub.Configuration.UAPubSubConnectionElement to OpcLabs.EasyOpc.UA.PubSub.UAPubSubConnectionDescriptor using the ToUAPubSubConnectionDescriptor static method instead.

The value of this parameter cannot be null (Nothing in Visual Basic).

Specifies how the incoming PubSub messages should be filtered before being delivered to the application.

Because the OpcLabs.EasyOpc.UA.PubSub.UASubscribeDataSetFilter has an implicit conversion from OpcLabs.EasyOpc.UA.PubSub.UAPublisherId, in languages that support implicit conversion operators (such as C# or VB.NET), you can simply use a OpcLabs.EasyOpc.UA.PubSub.UAPublisherId (containing the publisher Id that you want to allow in the filter) in place of this parameter, and the corresponding OPC UA subscribe dataset filter will be constructed automatically. When the implicit conversion operators are not supported (such as with Python.NET), you can use the FromUAPublisherId static method instead.

The value of this parameter cannot be null (Nothing in Visual Basic).

Metadata for the dataset.

The value of this parameter cannot be null (Nothing in Visual Basic).

The descriptor for the dataset field.

Because the OpcLabs.EasyOpc.UA.PubSub.UADataSetFieldDescriptor has implicit conversions from System.Guid and System.String, in languages that support implicit conversion operators (such as C# or VB.NET), you can simply use a GUID (representing the dataset field Id), or a string (representing the name of the dataset field) in place of this parameter, and the corresponding OPC UA dataset field descriptor will be constructed automatically. When the implicit conversion operators are not supported (such as with Python.NET), you can use the OpcLabs.EasyOpc.UA.PubSub.UADataSetFieldDescriptor.FromGuid or OpcLabs.EasyOpc.UA.PubSub.UADataSetFieldDescriptor.FromString static method instead.

The value of this parameter cannot be null (Nothing in Visual Basic).

Initializes a new instance of the class, specifying the callback, the state object, connection descriptor, filter, dataset metadata, and dataset field descriptor.
Syntax

Parameters

callback
A callback method to be invoked for each time a dataset field is received.

The value of this parameter cannot be null (Nothing in Visual Basic).

state
The state object (can be any value supplied by your code); available in event notifications.

The value of this parameter can be null (Nothing in Visual Basic).

connectionDescriptor
Descriptor for a PubSub connection (using physical parameters, or logical name).

Because the OpcLabs.EasyOpc.UA.PubSub.UAPubSubConnectionDescriptor has an implicit conversion from OpcLabs.BaseLib.Networking.ResourceAddress and System.String, in languages that support implicit conversion operators (such as C# or VB.NET), you can simply use a OpcLabs.BaseLib.Networking.ResourceAddress object, or a string (the so-called resource description string, usually a resource URL) in place of this parameter, and the corresponding OPC UA PubSub connection descriptor will be constructed automatically. When the implicit conversion operators are not supported (such as with Python.NET), you can use the FromResourceAddress or FromString static method instead.

Also, because the OpcLabs.EasyOpc.UA.PubSub.Configuration.UAPubSubConnectionElement has an implicit conversion to OpcLabs.EasyOpc.UA.PubSub.UAPubSubConnectionDescriptor, in languages that support implicit conversion operators (such as C# or VB.NET), you can simply use a OpcLabs.EasyOpc.UA.PubSub.Configuration.UAPubSubConnectionElement (from PubSub configuration) in place of this parameter, and the corresponding OPC UA PubSub connection descriptor will be constructed automatically. When the implicit conversion operators are not supported (such as with Python.NET), you can convert a OpcLabs.EasyOpc.UA.PubSub.Configuration.UAPubSubConnectionElement to OpcLabs.EasyOpc.UA.PubSub.UAPubSubConnectionDescriptor using the ToUAPubSubConnectionDescriptor static method instead.

The value of this parameter cannot be null (Nothing in Visual Basic).

filter
Specifies how the incoming PubSub messages should be filtered before being delivered to the application.

Because the OpcLabs.EasyOpc.UA.PubSub.UASubscribeDataSetFilter has an implicit conversion from OpcLabs.EasyOpc.UA.PubSub.UAPublisherId, in languages that support implicit conversion operators (such as C# or VB.NET), you can simply use a OpcLabs.EasyOpc.UA.PubSub.UAPublisherId (containing the publisher Id that you want to allow in the filter) in place of this parameter, and the corresponding OPC UA subscribe dataset filter will be constructed automatically. When the implicit conversion operators are not supported (such as with Python.NET), you can use the FromUAPublisherId static method instead.

The value of this parameter cannot be null (Nothing in Visual Basic).

dataSetMetaData
Metadata for the dataset.

The value of this parameter cannot be null (Nothing in Visual Basic).

dataSetFieldDescriptor
The descriptor for the dataset field.

Because the OpcLabs.EasyOpc.UA.PubSub.UADataSetFieldDescriptor has implicit conversions from System.Guid and System.String, in languages that support implicit conversion operators (such as C# or VB.NET), you can simply use a GUID (representing the dataset field Id), or a string (representing the name of the dataset field) in place of this parameter, and the corresponding OPC UA dataset field descriptor will be constructed automatically. When the implicit conversion operators are not supported (such as with Python.NET), you can use the OpcLabs.EasyOpc.UA.PubSub.UADataSetFieldDescriptor.FromGuid or OpcLabs.EasyOpc.UA.PubSub.UADataSetFieldDescriptor.FromString static method instead.

The value of this parameter cannot be null (Nothing in Visual Basic).

Requirements

Target Platforms: .NET Framework: Windows 10 (selected versions), Windows 11 (selected versions), Windows Server 2016, Windows Server 2022; .NET: Linux, macOS, Microsoft Windows

See Also