ReadMultipleNodeClasses Method

Reads value of NodeClass attribute of multiple nodes, using array of argument objects as an input.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
<ExtensionAttribute()>
<NotNullAttribute()>
Public Shared Function ReadMultipleNodeClasses( _
   ByVal client As IEasyUAClient, _
   ByVal nodeArgumentsArray() As UANodeArguments _
) As ValueResult(Of UANodeClass)()

'Usage
 
Dim client As IEasyUAClient
Dim nodeArgumentsArray() As UANodeArguments
Dim value() As ValueResult(Of UANodeClass)
 
value = IEasyUAClientExtension2.ReadMultipleNodeClasses(client, nodeArgumentsArray)

[Extension()]
[NotNull()]
public static ValueResult<UANodeClass>[] ReadMultipleNodeClasses( 
   IEasyUAClient client,
   UANodeArguments[] nodeArgumentsArray
)

[Extension()]
[NotNull()]
public:
static array<ValueResult<UANodeClass>^>^ ReadMultipleNodeClasses( 
   IEasyUAClient^ client,
   array<UANodeArguments^>^ nodeArgumentsArray
)

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).

nodeArgumentsArray

Array of OpcLabs.EasyOpc.UA.OperationModel.UANodeArguments. Array of argument objects specifying what to read from an OPC-UA server.

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

The individual elements of the parameter value cannot be null (Nothing in Visual Basic).

Return Value

Array of OpcLabs.BaseLib.OperationModel.Generic.ValueResult<T>. Returns an array of value objects. Each object contains the actual value of an attribute. The indices of elements in the output array are the same as those in the input array, .

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

This method also checks whether the returned value is not a reference, and is indeed of the OpcLabs.EasyOpc.UA.AddressSpace.UANodeClass type. The returned value is therefore always a valid OpcLabs.EasyOpc.UA.AddressSpace.UANodeClass.

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.

This is a multiple-operation method. In a properly written program, it 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 in the result objects returned by the method. For more information, see Multiple-operation Methods and 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

Reference

IEasyUAClientExtension2 Class
IEasyUAClientExtension2 Members

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