WaitForMultiple(IEasyUAClient,IReadOnlyList<ValueTuple<UAMonitoredItemArguments,Func<UAAttributeDataResult,Boolean>>>) Method

Waits until the attributes satisfy the given conditions. Specify arguments objects, and exit predicates based on OpcLabs.EasyOpc.UA.OperationModel.UAAttributeDataResult.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
<ExtensionAttribute()>
<NotNullAttribute()>
Public Overloads Shared Function WaitForMultiple( _
   ByVal client As IEasyUAClient, _
   ByVal argumentsAndExitPredicateList As IReadOnlyList(Of ValueTuple(Of UAMonitoredItemArguments,Func(Of UAAttributeDataResult,Boolean))) _
) As UAAttributeDataResult()

'Usage
 
Dim client As IEasyUAClient
Dim argumentsAndExitPredicateList As IReadOnlyList(Of ValueTuple(Of UAMonitoredItemArguments,Func(Of UAAttributeDataResult,Boolean)))
Dim value() As UAAttributeDataResult
 
value = IEasyUAClientExtension2.WaitForMultiple(client, argumentsAndExitPredicateList)

[Extension()]
[NotNull()]
public static UAAttributeDataResult[] WaitForMultiple( 
   IEasyUAClient client,
   IReadOnlyList<ValueTuple<UAMonitoredItemArguments,Func<UAAttributeDataResult,bool>>> argumentsAndExitPredicateList
)

[Extension()]
[NotNull()]
public:
static array<UAAttributeDataResult^>^ WaitForMultiple( 
   IEasyUAClient^ client,
   IReadOnlyList<ValueTuple<UAMonitoredItemArguments^,Func<UAAttributeDataResult^,bool>^>>^ argumentsAndExitPredicateList
)

Parameters

client

The client object that will perform the operation.

This is typically the OpcLabs.EasyOpc.UA.EasyUAClient object.

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

argumentsAndExitPredicateList

List of tuples, where each tuple consists of OPC-UA monitored item arguments, and a predicate on OpcLabs.EasyOpc.UA.OperationModel.UAAttributeDataResult determining when the wait is complete.

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

Return Value

The function returns an array of OpcLabs.EasyOpc.UA.OperationModel.UAAttributeDataResult objects. The indices of elements in the output array are the same as those in the input list, .

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

The individual elements of the returned value are never 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.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.

Remarks

The WaitForMultiple methods subscribe to the specified nodes&attributes, and monitor their data until the predicates specified for each item become true, or the alloted time elapses.

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

IEasyUAClientExtension2 Class
IEasyUAClientExtension2 Members
Overload List

Documentation Home, Send Documentation Feedback. Technical Support