OPC Studio User's Guide and Reference
Delete(IEasyUAFileTransfer,UAEndpointDescriptor,UANamedNodePath,String) Method



OpcLabs.EasyOpcUA Assembly > OpcLabs.EasyOpc.UA.FileTransfer Namespace > IEasyUAFileTransferExtension Class > Delete Method : Delete(IEasyUAFileTransfer,UAEndpointDescriptor,UANamedNodePath,String) Method
The OPC UA file transfer object that will perform the operation.

This is typically the EasyUAFileTransferClient object.

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

Endpoint descriptor. Identifies the OPC-UA server.

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).

A named node path of the OPC UA directory.

Because the OpcLabs.EasyOpc.UA.Navigation.UANamedNodePath has an implicit conversion from OpcLabs.EasyOpc.UA.UANodeDescriptor, in languages that support implicit conversion operators (such as C# or VB.NET), you can simply use a OpcLabs.EasyOpc.UA.UANodeDescriptor (containing the base and only node in the named node path) in place of this parameter, and the corresponding OPC UA named node path will be constructed automatically. When the implicit conversion operators are not supported (such as with Python.NET), you can use the OpcLabs.EasyOpc.UA.Navigation.UANamedNodePath.FromUANodeDescriptor static method instead.

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

A name of the existing OPC UA file or directory to delete.

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

Deletes an existing OPC UA file or directory, specifying the endpoint descriptor, directory named node path, and existing file or directory name.
Syntax
'Declaration
 
<ExtensionAttribute()>
Public Overloads Shared Sub Delete( _
   ByVal fileTransfer As IEasyUAFileTransfer, _
   ByVal endpointDescriptor As UAEndpointDescriptor, _
   ByVal directoryNamedNodePath As UANamedNodePath, _
   ByVal existingFileOrDirectoryName As String _
) 
'Usage
 
Dim fileTransfer As IEasyUAFileTransfer
Dim endpointDescriptor As UAEndpointDescriptor
Dim directoryNamedNodePath As UANamedNodePath
Dim existingFileOrDirectoryName As String
 
IEasyUAFileTransferExtension.Delete(fileTransfer, endpointDescriptor, directoryNamedNodePath, existingFileOrDirectoryName)

Parameters

fileTransfer
The OPC UA file transfer object that will perform the operation.

This is typically the EasyUAFileTransferClient object.

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

endpointDescriptor
Endpoint descriptor. Identifies the OPC-UA server.

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).

directoryNamedNodePath
A named node path of the OPC UA directory.

Because the OpcLabs.EasyOpc.UA.Navigation.UANamedNodePath has an implicit conversion from OpcLabs.EasyOpc.UA.UANodeDescriptor, in languages that support implicit conversion operators (such as C# or VB.NET), you can simply use a OpcLabs.EasyOpc.UA.UANodeDescriptor (containing the base and only node in the named node path) in place of this parameter, and the corresponding OPC UA named node path will be constructed automatically. When the implicit conversion operators are not supported (such as with Python.NET), you can use the OpcLabs.EasyOpc.UA.Navigation.UANamedNodePath.FromUANodeDescriptor static method instead.

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

existingFileOrDirectoryName
A name of the existing OPC UA file or directory to delete.

The value of this parameter cannot be 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 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

The directoryNamedNodePath must refer to an existing node in the server, of object type OpcLabs.EasyOpc.UA.AddressSpace.Standard.UAObjectTypeIds.FileDirectoryType.

This method throws a OpcLabs.EasyOpc.UA.OperationModel.UAException exception if the file or directory does not exist.

Recommendation: Whenever possible, do not use this method directly, and use a higher-level abstraction instead. See e.g. the GetWritableFileInfo(IEasyUAFileTransfer,UAEndpointDescriptor,UANamedNodeDescriptor) and GetWritableDirectoryContents(IEasyUAFileTransfer,UAEndpointDescriptor,UANamedNodePath) methods, which allow you to obtain objects that can be used to manage files and directories, in a way that is generic and not tied to OPC UA specifics.

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