QuickOPC User's Guide and Reference
BrowseServers(IEasyAEClient,String) Method
Example 



OpcLabs.EasyOpcClassicCore Assembly > OpcLabs.EasyOpc.AlarmsAndEvents Namespace > IEasyAEClientExtension Class > BrowseServers Method : BrowseServers(IEasyAEClient,String) Method
The client object that will perform the operation.
Name of the machine. Determines the computer to browse for OPC servers. May be an empty string, in which case the local computer will be browsed.
Browses for OPC (Alarms&Events) servers. Browses the specified computer and returns information about OPC (Alarms&Events) servers found.
Syntax
'Declaration
 
<ExtensionAttribute()>
<ElementsNotNullAttribute()>
<NotNullAttribute()>
Public Overloads Shared Function BrowseServers( _
   ByVal client As IEasyAEClient, _
   ByVal location As String _
) As ServerElementCollection
'Usage
 
Dim client As IEasyAEClient
Dim location As String
Dim value As ServerElementCollection
 
value = IEasyAEClientExtension.BrowseServers(client, location)
[Extension()]
[ElementsNotNull()]
[NotNull()]
public static ServerElementCollection BrowseServers( 
   IEasyAEClient client,
   string location
)
[Extension()]
[ElementsNotNull()]
[NotNull()]
public:
static ServerElementCollection^ BrowseServers( 
   IEasyAEClient^ client,
   String^ location
) 

Parameters

client
The client object that will perform the operation.
location
Name of the machine. Determines the computer to browse for OPC servers. May be an empty string, in which case the local computer will be browsed.

Return Value

The method returns a keyed collection of OpcLabs.EasyOpc.ServerElement values, each containing information about a particular OPC server found on the specified machine. The keys of the keyed collection are the server's CLSIDs.
Exceptions
ExceptionDescription

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.

The OPC "Classic" (or OPC XML-DA) 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.

Example

.NET

// This example shows how to obtain all ProgIDs of all OPC Alarms and Events servers on the local machine.

using System;
using System.Diagnostics;
using OpcLabs.EasyOpc;
using OpcLabs.EasyOpc.AlarmsAndEvents;
using OpcLabs.EasyOpc.OperationModel;

namespace DocExamples.AlarmsAndEvents._EasyAEClient
{
    class BrowseServers 
    { 
        public static void Main1()
        {
            // Instantiate the client object.
            var client = new EasyAEClient();

            ServerElementCollection serverElements;
            try
            {
                serverElements = client.BrowseServers("");
            }
            catch (OpcException opcException)
            {
                Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message);
                return;
            }

            foreach (ServerElement serverElement in serverElements)
            {
                Debug.Assert(serverElement != null);
                Console.WriteLine("serverElements[\"{0}\"].ProgId: {1}", serverElement.Clsid, serverElement.ProgId);
            }
        }
    } 
}
# This example shows how to obtain all ProgIDs of all OPC Data Access servers on the local machine.

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

# Import .NET namespaces.
from OpcLabs.EasyOpc.DataAccess import *
from OpcLabs.EasyOpc.OperationModel import *


# Instantiate the client object
client = EasyDAClient()

# Perform the operation
try:
    serverElements = IEasyDAClientExtension.BrowseServers(client, '')
except OpcException as opcException:
    print('*** Failure: ' + opcException.GetBaseException().Message)
    exit()

# Display results
for serverElement in serverElements:
    print('ServerElements("' + serverElement.ClsidString + '"): ' + serverElement.ProgId)
' This example shows how to obtain all ProgIDs of all OPC Alarms and Events servers on the local machine.

Imports OpcLabs.EasyOpc
Imports OpcLabs.EasyOpc.AlarmsAndEvents
Imports OpcLabs.EasyOpc.OperationModel

Namespace AlarmsAndEvents._EasyAEClient

    Friend Class BrowseServers
        Public Shared Sub Main1()
            Dim client = New EasyAEClient()

            Dim serverElements As ServerElementCollection
            Try
                serverElements = client.BrowseServers("")
            Catch opcException As OpcException
                Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message)
                Exit Sub
            End Try

            For Each serverElement As ServerElement In serverElements
                Debug.Assert(serverElement IsNot Nothing)
                Console.WriteLine("serverElements[""{0}""].ProgId: {1}", serverElement.Clsid, serverElement.ProgId)
            Next serverElement
        End Sub
    End Class

End Namespace
Requirements

Target Platforms: .NET Framework: Windows 10 (selected versions), Windows 11 (selected versions), Windows Server 2016, Windows Server 2022; .NET: Linux, macOS, Microsoft Windows

See Also