QuickOPC User's Guide and Reference
SubscribeDataSetField(IEasyUASubscriber,EasyUASubscribeDataSetFieldArguments) Method



OpcLabs.EasyOpcUA Assembly > OpcLabs.EasyOpc.UA.PubSub Namespace > IEasyUASubscriberExtension Class > SubscribeDataSetField Method : SubscribeDataSetField(IEasyUASubscriber,EasyUASubscribeDataSetFieldArguments) Method
The subscriber object that will perform the operation.
Holds all arguments needed to subscribe to a dataset field in OPC UA PubSub, including a callback method.
Subscribes to a single dataset field from a dataset, using arguments object.
Syntax
'Declaration
 
<ExtensionAttribute()>
Public Overloads Shared Function SubscribeDataSetField( _
   ByVal subscriber As IEasyUASubscriber, _
   ByVal subscribeDataSetFieldArguments As EasyUASubscribeDataSetFieldArguments _
) As Integer
'Usage
 
Dim subscriber As IEasyUASubscriber
Dim subscribeDataSetFieldArguments As EasyUASubscribeDataSetFieldArguments
Dim value As Integer
 
value = IEasyUASubscriberExtension.SubscribeDataSetField(subscriber, subscribeDataSetFieldArguments)

Parameters

subscriber
The subscriber object that will perform the operation.
subscribeDataSetFieldArguments
Holds all arguments needed to subscribe to a dataset field in OPC UA PubSub, including a callback method.

Return Value

Returns a dataset field subscription handle that can be used to change the subscription, obtain its arguments, or unsubscribe.
Exceptions
ExceptionDescription

A null reference (Nothing in Visual Basic) is passed to a method that does not accept it as a valid argument.

This is a usage error, i.e. it will never occur (the exception will not be thrown) in a correctly written program. Your code should not catch this exception.

Remarks

There is no corresponding method in COM.

 

This method operates (at least in part) asynchronously, with respect to the caller. The actual execution of the operation may be delayed, and the outcome of the operation (if any) is provided to the calling code using an event notification, callback, or other means explained in the text. In a properly written program, this method does not throw any exceptions. You should therefore not put try/catch statements or similar constructs around calls to this method. The only exceptions thrown by this method are for usage errors, i.e. when your code violates the usage contract of the method, such as passing in invalid arguments or calling the method when the state of the object does not allow it. Any operation-related errors (i.e. errors that depend on external conditions that your code cannot reliably check) are indicated by the means the operation returns its outcome (if any), which is described in the text. For more information, see Do not catch any exceptions with asynchronous or multiple-operation methods.
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