'Declaration
<ExtensionAttribute()> <NotNullAttribute()> Public Shared Function GetRootDirectory( _ ByVal fileTransfer As IEasyUAFileTransfer, _ ByVal endpointDescriptor As UAEndpointDescriptor, _ ByVal fileOrDirectoryNodeDescriptor As UANodeDescriptor _ ) As UANodeDescriptor
'Usage
Dim fileTransfer As IEasyUAFileTransfer Dim endpointDescriptor As UAEndpointDescriptor Dim fileOrDirectoryNodeDescriptor As UANodeDescriptor Dim value As UANodeDescriptor value = IEasyUAFileTransferExtension.GetRootDirectory(fileTransfer, endpointDescriptor, fileOrDirectoryNodeDescriptor)
[Extension()] [NotNull()] public static UANodeDescriptor GetRootDirectory( IEasyUAFileTransfer fileTransfer, UAEndpointDescriptor endpointDescriptor, UANodeDescriptor fileOrDirectoryNodeDescriptor )
[Extension()] [NotNull()] public: static UANodeDescriptor^ GetRootDirectory( IEasyUAFileTransfer^ fileTransfer, UAEndpointDescriptor^ endpointDescriptor, UANodeDescriptor^ fileOrDirectoryNodeDescriptor )
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). - fileOrDirectoryNodeDescriptor
- The directory node descriptor of the file or directory for which the root directory should be obtained.
Because the OpcLabs.EasyOpc.UA.UANodeDescriptor has implicit conversions from OpcLabs.EasyOpc.UA.AddressSpace.UANodeId, OpcLabs.EasyOpc.UA.AddressSpace.UANodeElement, OpcLabs.EasyOpc.UA.Navigation.UABrowsePath and System.String, in languages that support implicit conversion operators (such as C# or VB.NET), you can simply use a OpcLabs.EasyOpc.UA.AddressSpace.UANodeId object (representing the Id of the OPC UA node), a node element object (from OPC UA browsing), OpcLabs.EasyOpc.UA.Navigation.UABrowsePath object (representing OPC UA absolute browse path), or a string (with expanded node Id text) in place of this parameter, and the corresponding node 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.UANodeDescriptor.FromString, OpcLabs.EasyOpc.UA.UANodeDescriptor.FromUABrowsePath, OpcLabs.EasyOpc.UA.UANodeDescriptor.FromUANodeElement or OpcLabs.EasyOpc.UA.UANodeDescriptor.FromUANodeId static method instead.
If you are using OPC Wizard (for server development), an implicit conversion from OpcLabs.EasyOpc.UA.NodeSpace.UAServerNode can be used in the same way to simply pass the server node in place of this parameter, which will use its OpcLabs.EasyOpc.UA.NodeSpace.UAServerNode.EffectiveNodeDescriptor property for the operation.
The value of this parameter cannot be
null
(Nothing
in Visual Basic).
Return Value
Because there are implicit conversions to OpcLabs.EasyOpc.UA.Navigation.UANamedNodeDescriptor and OpcLabs.EasyOpc.UA.Navigation.UANamedNodePath from OpcLabs.EasyOpc.UA.UANodeDescriptor, in languages that support implicit conversion operators (such as C# or VB.NET), you can simply use the returned OpcLabs.EasyOpc.UA.UANodeDescriptor in any place where OpcLabs.EasyOpc.UA.Navigation.UANamedNodeDescriptor is expected (in this case the OpcLabs.EasyOpc.UA.UANodeDescriptor contains the final node descriptor) or where OpcLabs.EasyOpc.UA.Navigation.UANamedNodePath is expected (in this case the OpcLabs.EasyOpc.UA.UANodeDescriptor contains the base and only node in the named node path), and the corresponding OPC UA named node descriptor or 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.UANamedNodeDescriptor.FromUANodeDescriptor or OpcLabs.EasyOpc.UA.Navigation.UANamedNodePath.FromUANodeDescriptor static method instead.
This method never returns null
(Nothing
in Visual Basic).