TestSubscriptionAsync Method

Tests whether an OPC UA PubSub subscription can be successfully established. Asynchronous.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
<ExtensionAttribute()>
<AsyncThrowsAttribute(OpcLabs.EasyOpc.UA.OperationModel.UAException)>
<NotNullAttribute()>
Public Shared Function TestSubscriptionAsync( _
   ByVal subscriber As IEasyUASubscriber, _
   ByVal subscribeDataSetArguments As UASubscribeDataSetArguments, _
   ByVal millisecondsTimeout As Integer _
) As Task(Of UADataSetData)

'Usage
 
Dim subscriber As IEasyUASubscriber
Dim subscribeDataSetArguments As UASubscribeDataSetArguments
Dim millisecondsTimeout As Integer
Dim value As Task(Of UADataSetData)
 
value = IEasyUASubscriberExtension2.TestSubscriptionAsync(subscriber, subscribeDataSetArguments, millisecondsTimeout)

[Extension()]
[AsyncThrows(OpcLabs.EasyOpc.UA.OperationModel.UAException)]
[NotNull()]
public static Task<UADataSetData> TestSubscriptionAsync( 
   IEasyUASubscriber subscriber,
   UASubscribeDataSetArguments subscribeDataSetArguments,
   int millisecondsTimeout
)

[Extension()]
[AsyncThrows(OpcLabs.EasyOpc.UA.OperationModel.UAException)]
[NotNull()]
public:
static Task<UADataSetData^>^ TestSubscriptionAsync( 
   IEasyUASubscriber^ subscriber,
   UASubscribeDataSetArguments^ subscribeDataSetArguments,
   int millisecondsTimeout
)

Parameters

subscriber

The subscriber object that will perform the operation.

This is typically the OpcLabs.EasyOpc.UA.PubSub.EasyUASubscriber object.

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

subscribeDataSetArguments

Arguments needed to subscribe to a dataset.

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

millisecondsTimeout

A period during which a dataset should be received.

Valid values of this parameter are in the range from 0 to 2147483647 (Int32.MaxValue).

Return Value

The method returns a task. The task returns non-null OpcLabs.EasyOpc.UA.PubSub.UADataSetData when the test passes and a dataset has been received, or a null reference if there is no error, but no dataset has been received during the period. The task throws a OpcLabs.EasyOpc.UA.OperationModel.UAException when there is an error establishing the subscription.

This method never returns null (Nothing in Visual Basic).

Exceptions

Exception Description

Exception	Description
System.ArgumentNullException	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.
System.ArgumentOutOfRangeException	The value of an argument is outside the allowable range of values as defined by the invoked method. 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.

System.ArgumentNullException

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.

System.ArgumentOutOfRangeException

The value of an argument is outside the allowable range of values as defined by the invoked method.

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

This is an asynchronous method. For a synchronous alternative, see TestSubscription.

This is an extension method (info: C#, VB.NET). In languages that have support for extensions methods (such as C# and VB.NET), you can use the extension method as if it were a regular method on the object that is its first parameter. In other languages (such as with Python.NET), you will call the extension as a static method, and pass it the object on which it acts as its first parameter.

Requirements

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

Reference

IEasyUASubscriberExtension2 Class
IEasyUASubscriberExtension2 Members

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