ReadDataType(IEasyUAClient,UANodeArguments) Method

Reads a value of DataType attribute of a node, using an arguments object that holds the node information.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
<ExtensionAttribute()>
<NotNullAttribute()>
Public Overloads Shared Function ReadDataType( _
   ByVal client As IEasyUAClient, _
   ByVal nodeArguments As UANodeArguments _
) As UANodeId

'Usage
 
Dim client As IEasyUAClient
Dim nodeArguments As UANodeArguments
Dim value As UANodeId
 
value = IEasyUAClientExtension2.ReadDataType(client, nodeArguments)

[Extension()]
[NotNull()]
public static UANodeId ReadDataType( 
   IEasyUAClient client,
   UANodeArguments nodeArguments
)

[Extension()]
[NotNull()]
public:
static UANodeId^ ReadDataType( 
   IEasyUAClient^ client,
   UANodeArguments^ nodeArguments
)

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).

nodeArguments

An arguments object that specifies the node in the OPC server.

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

Return Value

Because there is an implicit conversion from OpcLabs.EasyOpc.UA.AddressSpace.UANodeId to OpcLabs.EasyOpc.UA.UANodeDescriptor, in languages that support implicit conversion operators (such as C# or VB.NET), you can simply use the returned OpcLabs.EasyOpc.UA.AddressSpace.UANodeId in any place where the OpcLabs.EasyOpc.UA.UANodeDescriptor is expected as input, and the corresponding node descriptor will be constructed automatically.

Also, because the OpcLabs.EasyOpc.UA.AddressSpace.UANodeId has an implicit conversion to System.String, and it converts to the expanded text of the node Id (OpcLabs.EasyOpc.UA.AddressSpace.UANodeId.ExpandedText), in languages that support implicit conversion operators (such as C# or VB.NET), you can simply use the returned OpcLabs.EasyOpc.UA.AddressSpace.UANodeId in any place where expanded text of a node Id (a string) is expected as input, and the corresponding expanded text will be taken automatically from the node Id.

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.
OpcLabs.EasyOpc.UA.OperationModel.UAException	The OPC UA operation has failed. This operation exception in uniformly used to allow common handling of various kinds of errors. The System.Exception.InnerException always contains information about the actual error cause. This is an operation error that depends on factors external to your program, and thus cannot be always avoided. Your code must handle it appropriately.

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.

OpcLabs.EasyOpc.UA.OperationModel.UAException

The OPC UA operation has failed. This operation exception in uniformly used to allow common handling of various kinds of errors. The System.Exception.InnerException always contains information about the actual error cause.

This is an operation error that depends on factors external to your program, and thus cannot be always avoided. Your code must handle it appropriately.

Remarks

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

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