OPC Studio User's Guide and Reference
BrowseNodes(IEasyAEClient,String,String,String,AEBrowseParameters) Method



OpcLabs.EasyOpcClassicCore Assembly > OpcLabs.EasyOpc.AlarmsAndEvents Namespace > IEasyAEClientExtension Class > BrowseNodes Method : BrowseNodes(IEasyAEClient,String,String,String,AEBrowseParameters) Method
The client object that will perform the operation.

This is typically the EasyAEClient object.

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

Name of the machine. Determines the computer on which the OPC server is located. It may be an empty string, in which case the OPC server is assumed to exist on the local computer or at the computer specified for it by DCOM configuration.

The value represents a UNC or DNS computer name. Any string can be passed to this parameter (i.e. will not cause System.ArgumentException), but not all values make sense and will work when an operation using them is attempted. IPv6 addresses are normally enclosed between '[' and ']'.

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

Contains ProgID of the OPC server.

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

Fully qualified name of the parent area to be browsed (empty string for root)

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

Contains filtering conditions.

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

Browses the specified area for child areas. Uses computer name and server class for specifying the OPC server. A parent area name is passed in.
Syntax
'Declaration
 
<ExtensionAttribute()>
<NotNullAttribute()>
Public Overloads Shared Function BrowseNodes( _
   ByVal client As IEasyAEClient, _
   ByVal machineName As String, _
   ByVal serverClass As String, _
   ByVal parentQualifiedName As String, _
   ByVal browseParameters As AEBrowseParameters _
) As AENodeElementCollection
'Usage
 
Dim client As IEasyAEClient
Dim machineName As String
Dim serverClass As String
Dim parentQualifiedName As String
Dim browseParameters As AEBrowseParameters
Dim value As AENodeElementCollection
 
value = IEasyAEClientExtension.BrowseNodes(client, machineName, serverClass, parentQualifiedName, browseParameters)

Parameters

client
The client object that will perform the operation.

This is typically the EasyAEClient object.

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

machineName
Name of the machine. Determines the computer on which the OPC server is located. It may be an empty string, in which case the OPC server is assumed to exist on the local computer or at the computer specified for it by DCOM configuration.

The value represents a UNC or DNS computer name. Any string can be passed to this parameter (i.e. will not cause System.ArgumentException), but not all values make sense and will work when an operation using them is attempted. IPv6 addresses are normally enclosed between '[' and ']'.

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

serverClass
Contains ProgID of the OPC server.

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

parentQualifiedName
Fully qualified name of the parent area to be browsed (empty string for root)

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

browseParameters
Contains filtering conditions.

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

Return Value

The method returns a keyed collection of OpcLabs.EasyOpc.AlarmsAndEvents.AddressSpace.AENodeElement values, each containing information about a particular node (area or source) found. The keys of the keyed collection are the names of the nodes.

This method never returns null (Nothing in Visual Basic).

The individual elements of the returned value are never null (Nothing in Visual Basic).

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.

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

See Also