GetApplication Method (EasyUAGlobalDiscoveryClientCore)

Endpoint descriptor. Identifies the OPC-UA server. The server must be a Global Directory Server (GDS).

Because the OpcLabs.EasyOpc.UA.UAEndpointDescriptor has implicit conversions from System.String and System.Uri, in languages that support implicit conversion operators (such as C# or VB.NET), you can simply use a string (representing the endpoint URL, or a so-called OPC UA endpoint descriptor string), or a System.Uri object, in place of this parameter, and the corresponding endpoint descriptor will be constructed automatically. When the implicit conversion operators are not supported (such as with Python.NET), you can use the OpcLabs.EasyOpc.UA.UAEndpointDescriptor.FromString or OpcLabs.EasyOpc.UA.UAEndpointDescriptor.FromUri static method instead.

Also, because the OpcLabs.EasyOpc.UA.Discovery.UAApplicationElement and OpcLabs.EasyOpc.UA.Discovery.UADiscoveryElement have an implicit conversion to OpcLabs.EasyOpc.UA.UAEndpointDescriptor, in languages that support implicit conversion operators (such as C# or VB.NET), you can simply use a OpcLabs.EasyOpc.UA.Discovery.UAApplicationElement or OpcLabs.EasyOpc.UA.Discovery.UADiscoveryElement (results from OPC UA discovery) in place of this parameter, and the corresponding endpoint descriptor will be constructed automatically. When the implicit conversion operators are not supported (such as with Python.NET), you can convert a (non-null) OpcLabs.EasyOpc.UA.Discovery.UAApplicationElement or OpcLabs.EasyOpc.UA.Discovery.UADiscoveryElement to OpcLabs.EasyOpc.UA.UAEndpointDescriptor using the ToUAEndpointDescriptor or ToUAEndpointDescriptor method instead.

If you are using OPC Wizard (for server development), an implicit conversion from OpcLabs.EasyOpc.UA.EasyUAServerCore can be used in the same way to simply pass the server object in place of this parameter, which will use its OpcLabs.EasyOpc.UA.EasyUAServerCore.EffectiveServerDescriptor property for the connection.

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

Gets a specific application record for an OPC UA application known to GDS.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
Public Function GetApplication( _
   ByVal gdsEndpointDescriptor As UAEndpointDescriptor, _
   ByVal applicationId As UANodeId _
) As UAApplicationRecordDataType

'Usage
 
Dim instance As EasyUAGlobalDiscoveryClientCore
Dim gdsEndpointDescriptor As UAEndpointDescriptor
Dim applicationId As UANodeId
Dim value As UAApplicationRecordDataType
 
value = instance.GetApplication(gdsEndpointDescriptor, applicationId)

public UAApplicationRecordDataType GetApplication( 
   UAEndpointDescriptor gdsEndpointDescriptor,
   UANodeId applicationId
)

public:
UAApplicationRecordDataType^ GetApplication( 
   UAEndpointDescriptor^ gdsEndpointDescriptor,
   UANodeId^ applicationId
)

Parameters

gdsEndpointDescriptor

Endpoint descriptor. Identifies the OPC-UA server. The server must be a Global Directory Server (GDS).

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

applicationId

The application ID that identifies the application of interest.

Because the OpcLabs.EasyOpc.UA.AddressSpace.UANodeId has an implicit conversion from System.String, in languages that support implicit conversion operators (such as C# or VB.NET), you can simply use a string (representing the expanded text of the nodeId) in place of this parameter, and the corresponding OPC UA node Id will be constructed automatically. When the implicit conversion operators are not supported (such as with Python.NET), you can use the OpcLabs.EasyOpc.UA.AddressSpace.UANodeId.UANodeId Constructor(String) constructor instead.

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

Return Value

Returns the application record (UAApplicationRecordDataType) that matches the application ID given by .

Because OpcLabs.EasyOpc.UA.Discovery.UAApplicationElement has an implicit conversion to OpcLabs.EasyOpc.UA.UAEndpointDescriptor, you can simply use the returned OpcLabs.EasyOpc.UA.Discovery.UAApplicationElement in any place where OpcLabs.EasyOpc.UA.UAEndpointDescriptor is expected as input, and the corresponding endpoint descriptor will be constructed automatically from the application element. When the implicit conversion operators are not supported (such as with Python.NET), you can use the ToUAEndpointDescriptor static method instead.

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

If you want to find the registration information for the current client application, it is recommended that you use the higher-level OpcLabs.EasyOpc.UA.Application.IEasyUAClientServerApplication.FindGdsRegistrations method instead.

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

EasyUAGlobalDiscoveryClientCore Class
EasyUAGlobalDiscoveryClientCore Members

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