UnregisterApplication Method (_EasyUAGlobalDiscoveryClient)

Removes an application from a Global Discovery Server.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
Sub UnregisterApplication( _
   ByVal gdsEndpointDescriptor As Object, _
   ByVal applicationId As Object _
)

'Usage
 
Dim instance As _EasyUAGlobalDiscoveryClient
Dim gdsEndpointDescriptor As Object
Dim applicationId As Object
 
instance.UnregisterApplication(gdsEndpointDescriptor, applicationId)

void UnregisterApplication( 
   object gdsEndpointDescriptor,
   object applicationId
)

void UnregisterApplication( 
   Object^ gdsEndpointDescriptor,
   Object^ applicationId
)

Parameters

gdsEndpointDescriptor: Endpoint descriptor. Identifies the OPC-UA server. The server must be a Global Directory Server (GDS).
applicationId: The identifier assigned by the GDS to the application.

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 unregister the current client application, it is recommended that you use the higher-level OpcLabs.EasyOpc.UA.Application.IEasyUAClientServerApplication.UnregisterFromGds method instead.

Example

.NET

// Shows how to unregister all clients from a GDS.

using System;
using System.Collections.Generic;
using System.Linq;
using OpcLabs.BaseLib.Collections.Generic.Extensions;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.AddressSpace;
using OpcLabs.EasyOpc.UA.Discovery;
using OpcLabs.EasyOpc.UA.Extensions;
using OpcLabs.EasyOpc.UA.Gds;
using OpcLabs.EasyOpc.UA.OperationModel;

namespace UADocExamples.Gds._EasyUAGlobalDiscoveryClient
{
    class UnregisterApplication
    {
        public static void Main1()
        {
            // Define which GDS we will work with.
            UAEndpointDescriptor gdsEndpointDescriptor =
                ((UAEndpointDescriptor)"opc.tcp://opcua.demo-this.com:58810/GlobalDiscoveryServer")
                .WithUserNameIdentity("appadmin", "demo");

            // Instantiate the global discovery client object
            var globalDiscoveryClient = new EasyUAGlobalDiscoveryClient();

            // Find application IDs of all client applications registered in the GDS.
            var clientApplicationIds = new HashSet<UANodeId>();
            try
            {
                globalDiscoveryClient.QueryApplications(
                    gdsEndpointDescriptor: gdsEndpointDescriptor,
                    startingRecordId: 0,
                    maximumRecordsToReturn: 0,
                    applicationName: "",
                    applicationUriString: "",
                    applicationTypes: UAApplicationTypes.Client,
                    productUriString: "",
                    serverCapabilities: new string[0],
                    lastCounterResetTime: out _,
                    nextRecordId: out _,
                    applications: out UAApplicationDescription[] applicationDescriptionArray);

                foreach (UAApplicationDescription applicationDescription in applicationDescriptionArray)
                {
                    var applicationRecordArray = globalDiscoveryClient.FindApplications(
                        gdsEndpointDescriptor,
                        applicationDescription.ApplicationUriString);
                    clientApplicationIds.AddRange(applicationRecordArray.Select(description => description.ApplicationId));
                }
            }
            catch (UAException uaException)
            {
                Console.WriteLine("*** Failure: {0}", uaException.GetBaseException().Message);
                return;
            }

            // Unregister all client applications found.
            foreach (UANodeId applicationId in clientApplicationIds)
            {
                Console.WriteLine();
                Console.WriteLine("Application ID: {0}", applicationId);

                try
                {
                    globalDiscoveryClient.UnregisterApplication(gdsEndpointDescriptor, applicationId);
                }
                catch (UAException uaException)
                {
                    Console.WriteLine("*** Failure: {0}", uaException.GetBaseException().Message);
                    continue;
                }
                Console.WriteLine("Unregistered.");
            }
        }
    }
}

# Shows how to unregister all clients from a GDS.

# The QuickOPC package is needed. Install it using "pip install opclabs_quickopc".
import opclabs_quickopc

# Import .NET namespaces.
from System import *
from OpcLabs.EasyOpc.UA import *
from OpcLabs.EasyOpc.UA.Discovery import *
from OpcLabs.EasyOpc.UA.Extensions import *
from OpcLabs.EasyOpc.UA.Gds import *
from OpcLabs.EasyOpc.UA.OperationModel import *


# Define which GDS we will work with.
gdsEndpointDescriptor = UAEndpointDescriptor('opc.tcp://opcua.demo-this.com:58810/GlobalDiscoveryServer')
gdsEndpointDescriptor = UAEndpointDescriptorExtension.WithUserNameIdentity(gdsEndpointDescriptor,
                                                                           'appadmin', 'demo')

# Instantiate the global discovery client object.
globalDiscoveryClient = EasyUAGlobalDiscoveryClient()

# Find application IDs of all client applications registered in the GDS.
clientApplicationIds = set()
try:
    _, _, _, applicationDescriptionArray = globalDiscoveryClient.QueryApplications(
        gdsEndpointDescriptor,
        0,  # startingRecordId
        0,  # maximumRecordsToReturn
        '', # applicationName
        '', # applicationUriString
        UAApplicationTypes.Client, # applicationTypes
        '', # productUriString
        Array.Empty[String](),  # serverCapabilities
        DateTime(), # out lastCounterResetTime
        0,  # out nextRecordId
        Array.Empty[UAApplicationDescription]()) # out applications

    for applicationDescription in applicationDescriptionArray:
        applicationRecordArray = globalDiscoveryClient.FindApplications(
            gdsEndpointDescriptor,
            applicationDescription.ApplicationUriString)
        for applicationRecord in applicationRecordArray:
            clientApplicationIds.add(applicationRecord.ApplicationId)

except UAException as uaException:
    print('*** Failure: ' + uaException.GetBaseException().Message)
    exit()

# Unregister all client applications found.
for applicationId in clientApplicationIds:
    print()
    print('Application ID: ', applicationId, sep='')

    try:
        globalDiscoveryClient.UnregisterApplication(gdsEndpointDescriptor, applicationId)
    except UAException as uaException:
        print('*** Failure: ' + uaException.GetBaseException().Message)
        continue
    print('Application unregistered.')

print()
print('Finished.')

' Shows how to unregister all clients from a GDS.

Imports System.Linq
Imports OpcLabs.BaseLib.Collections.Generic.Extensions
Imports OpcLabs.EasyOpc.UA
Imports OpcLabs.EasyOpc.UA.AddressSpace
Imports OpcLabs.EasyOpc.UA.Discovery
Imports OpcLabs.EasyOpc.UA.Extensions
Imports OpcLabs.EasyOpc.UA.Gds
Imports OpcLabs.EasyOpc.UA.OperationModel

Namespace Gds._EasyUAGlobalDiscoveryClient
    Friend Class UnregisterApplication
        Public Shared Sub Main1()

            ' Define which GDS we will work with.
            Dim gdsEndpointDescriptor As UAEndpointDescriptor =
                New UAEndpointDescriptor("opc.tcp://opcua.demo-this.com:58810/GlobalDiscoveryServer") _
                .WithUserNameIdentity("appadmin", "demo")

            ' Instantiate the global discovery client object
            Dim globalDiscoveryClient = New EasyUAGlobalDiscoveryClient()

            ' Find application IDs of all client applications registered in the GDS.
            Dim clientApplicationIds = New HashSet(Of UANodeId)
            Try
                Dim lastCounterResetTime As DateTime
                Dim nextRecordId As Long
                Dim applicationDescriptionArray() As UAApplicationDescription = Nothing
                globalDiscoveryClient.QueryApplications(
                    gdsEndpointDescriptor:=gdsEndpointDescriptor,
                    startingRecordId:=0,
                    maximumRecordsToReturn:=0,
                    applicationName:="",
                    applicationUriString:="",
                    applicationTypes:=UAApplicationTypes.Client,
                    productUriString:="",
                    serverCapabilities:=New String() {},
                    lastCounterResetTime:=lastCounterResetTime,
                    nextRecordId:=nextRecordId,
                    applications:=applicationDescriptionArray)

                For Each applicationDescription As UAApplicationDescription In applicationDescriptionArray
                    Dim applicationRecordArray = globalDiscoveryClient.FindApplications(
                        gdsEndpointDescriptor,
                        applicationDescription.ApplicationUriString)
                    clientApplicationIds.AddRange(applicationRecordArray.Select(Function(description) description.ApplicationId))
                Next applicationDescription
            Catch uaException As UAException
                Console.WriteLine("*** Failure: {0}", uaException.GetBaseException.Message)
                Exit Sub
            End Try

            ' Unregister all client applications found.
            For Each applicationId As UANodeId In clientApplicationIds
                Console.WriteLine()
                Console.WriteLine("Application ID: {0}", applicationId)

                Try
                    globalDiscoveryClient.UnregisterApplication(gdsEndpointDescriptor, applicationId)
                Catch uaException As UAException
                    Console.WriteLine("*** Failure: {0}", uaException.GetBaseException.Message)
                    Continue For
                End Try
                Console.WriteLine("Unregistered.")
            Next applicationId
        End Sub
    End Class
End Namespace

Object Pascal

// Shows how to unregister all clients from a GDS.

class procedure UnregisterApplication.Main;
var
  ApplicationDescription: _UAApplicationDescription;
  ApplicationDescriptionArray: OleVariant;
  ApplicationId: _UANodeId;
  ApplicationName: WideString;
  ApplicationRecord: _UAApplicationRecordDataType;
  ApplicationRecordArray: OleVariant;
  ApplicationUriString: WideString;
  ClientApplicationIds: TList<_UANodeID>;
  GlobalDiscoveryClient: OpcLabs_EasyOpcUA_TLB._EasyUAGlobalDiscoveryClient;
  GdsEndpointDescriptor: _UAEndpointDescriptor;
  I, J: integer;
  LastCounterResetTime: TDateTime;
  MaximumRecordsToReturn: Integer;
  NextRecordId: Integer;
  ProductUriString: WideString;
  ServerCapabilities: array of string;
  StartingRecordId: Integer;
begin
  // Define which GDS we will work with.
  GdsEndpointDescriptor := CoUAEndpointDescriptor.Create;
  GdsEndpointDescriptor.UrlString := 'opc.tcp://opcua.demo-this.com:58810/GlobalDiscoveryServer';
  GdsEndpointDescriptor.UserIdentity.UserNameTokenInfo.UserName := 'appadmin';
  GdsEndpointDescriptor.UserIdentity.UserNameTokenInfo.Password := 'demo';

  // Instantiate the global discovery client object
  GlobalDiscoveryClient := CoEasyUAGlobalDiscoveryClient.Create;

  // Find application IDs of all client applications registered in the GDS.
  ClientApplicationIds := TList<_UANodeID>.Create();
  StartingRecordId := 0;
  MaximumRecordsToReturn := 0;
  ApplicationName := '';
  ApplicationUriString := '';
  ProductUriString := '';
  try
    GlobalDiscoveryClient.QueryApplications(
      GdsEndpointDescriptor,
      StartingRecordId,
      MaximumRecordsToReturn,
      ApplicationName,
      ApplicationUriString,
      UAApplicationTypes_Client,
      ProductUriString,
      ServerCapabilities,
      LastCounterResetTime,
      NextRecordId,
      ApplicationDescriptionArray);

    for I := VarArrayLowBound(ApplicationDescriptionArray,1) to VarArrayHighBound(ApplicationDescriptionArray,1) do
    begin
      ApplicationDescription := IUnknown(ApplicationDescriptionArray[I]) as _UAApplicationDescription;
      TVarData(ApplicationRecordArray).VType := varArray or varVariant;
      TVarData(ApplicationRecordArray).VArray := PVarArray(GlobalDiscoveryClient.FindApplications(
        GdsEndpointDescriptor, ApplicationDescription.ApplicationUriString));
      for J := VarArrayLowBound(ApplicationRecordArray,1) to VarArrayHighBound(ApplicationRecordArray,1) do
      begin
        ApplicationRecord := IUnknown(ApplicationRecordArray[J]) as _UAApplicationRecordDataType;
        ClientApplicationIds.Add(ApplicationRecord.ApplicationId);
      end;
    end;
  except
    on E: EOleException do
    begin
      WriteLn(Format('*** Failure: %s', [E.GetBaseException.Message]));
    end;
  end;

  // Unregister all client applications found.
  for ApplicationId in ClientApplicationIds do
  begin
    WriteLn;
    WriteLn('Application ID: ', ApplicationId.ToString);
    try
      GlobalDiscoveryClient.UnregisterApplication(
        GdsEndpointDescriptor, ApplicationId);
    except
      on E: EOleException do
      begin
        WriteLn(Format('*** Failure: %s', [E.GetBaseException.Message]));
        Continue;
      end;
    end;
    WriteLn('Unregistered.');
  end;
  FreeAndNil(ClientApplicationIds);
end;

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

_EasyUAGlobalDiscoveryClient Interface
_EasyUAGlobalDiscoveryClient Members

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