Parameters
- subpath
- Relative path that identifies the file.
The value of this parameter can be
null
(Nothing
in Visual Basic).
Return Value
This method never returns null
(Nothing
in Visual Basic).
OpcLabs.BaseLib Assembly > OpcLabs.BaseLib.Extensions.FileProviders Namespace > MappedFileProvider Class : GetFileInfo2 Method |
The value of this parameter can be null
(Nothing
in Visual Basic).
public IFileInfo2 GetFileInfo2( string subpath )
public: IFileInfo2^ GetFileInfo2( String^ subpath )
'Declaration
Public Function GetFileInfo2( _ ByVal subpath As String _ ) As IFileInfo2
'Usage
Dim instance As MappedFileProvider Dim subpath As String Dim value As IFileInfo2 value = instance.GetFileInfo2(subpath)
The value of this parameter can be null
(Nothing
in Visual Basic).
This method never returns null
(Nothing
in Visual Basic).
For Microsoft.Extensions.FileProviders.IDirectoryContents, IDirectory2, IDirectoryContents2, IWritableDirectory and IWritableDirectoryContents, relative paths are based on the directory itself; absolute paths are based on the root directory of the file provider. Notice the difference from Microsoft.Extensions.FileProviders.IFileInfo, IFileInfo2 and IWritableFileInfo, where relative paths are based on the directory where the file is located.
This method or property does not throw any exceptions, aside from execution exceptions such as System.Threading.ThreadAbortException or System.OutOfMemoryException.
// Shows how to open a file stream for reading, and read its content using a text reader object, using OPC UA file provider // model. // // Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html . // OPC client and subscriber examples in C# on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-CSharp . // Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own // a commercial license in order to use Online Forums, and we reply to every post. using System; using System.IO; using OpcLabs.BaseLib.Extensions.FileProviders; using OpcLabs.EasyOpc.UA; using OpcLabs.EasyOpc.UA.FileTransfer; namespace UADocExamples.FileProviders._FileInfo2 { class ReadText { public static void Main1() { // Unified Automation .NET based demo server (UaNETServer/UaServerNET.exe) UAEndpointDescriptor endpointDescriptor = "opc.tcp://localhost:48030"; // A node that represents an instance of OPC UA FileType object. UANodeDescriptor fileNodeDescriptor = "nsu=http://www.unifiedautomation.com/DemoServer/ ;s=Demo.Files.TextFile"; // Instantiate the file transfer client object var fileTransferClient = new EasyUAFileTransferClient(); Console.WriteLine("Getting file info..."); IFileInfo2 fileInfo2 = fileTransferClient.GetFileInfo2(endpointDescriptor, fileNodeDescriptor); // From this point onwards, the code is independent of the concrete realization of the file provider, and would // be identical e.g. for files in the physical file system, if the corresponding file provider was used. try { // Get a stream reader object that corresponds to an OPC UA file. Console.WriteLine("Opening the file for reading..."); // We know that the file contains text, so we read it using a stream reader. If the file content was // binary, you would process the stream according to the data format. using (StreamReader streamReader = fileInfo2.CreateStreamReader()) { // Read in the text from the file and display it line by line. Console.WriteLine(); Console.WriteLine("Reading text lines:"); int i = 0; while (!streamReader.EndOfStream) { string line = streamReader.ReadLine(); Console.WriteLine($"[{i}] {line}"); i++; } } } // Methods in the file provider model throw IOException and other exceptions, but not UAException. catch (Exception exception) { Console.WriteLine($"*** Failure: {exception.GetBaseException().Message}"); return; } Console.WriteLine(); Console.WriteLine("Finished..."); } } }
# Shows how to open a file stream for reading, and read its content using a text reader object, using OPC UA file provider # model. # # Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html . # OPC client and subscriber examples in PowerShell on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-PowerShell . # Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own # a commercial license in order to use Online Forums, and we reply to every post. #requires -Version 5.1 using namespace System.IO using namespace OpcLabs.BaseLib.Extensions.FileProviders using namespace OpcLabs.EasyOpc.UA using namespace OpcLabs.EasyOpc.UA.FileTransfer # The path below assumes that the current directory is [ProductDir]/Examples-NET/PowerShell/Windows . Add-Type -Path "../../../Components/Opclabs.QuickOpc/net472/OpcLabs.EasyOpcUA.dll" Add-Type -Path "../../../Components/Opclabs.QuickOpc/net472/OpcLabs.EasyOpcUAComponents.dll" # Unified Automation .NET based demo server (UaNETServer/UaServerNET.exe) [UAEndpointDescriptor]$endpointDescriptor = "opc.tcp://localhost:48030" # A node that represents an instance of OPC UA FileType object. [UANodeDescriptor]$fileNodeDescriptor = "nsu=http://www.unifiedautomation.com/DemoServer/ ;s=Demo.Files.TextFile" # Instantiate the file transfer client object. $fileTransferClient = New-Object EasyUAFileTransferClient Write-Host "Getting file info..." [IFileInfo2]$fileInfo2 = [IEasyUAFileTransferExtension]::GetFileInfo2($fileTransferClient, $endpointDescriptor, $fileNodeDescriptor) # From this point onwards, the code is independent of the concrete realization of the file provider, and would # be identical e.g. for files in the physical file system, if the corresponding file provider was used. try { # Get a stream reader object that corresponds to an OPC UA file. Write-Host "Opening the file for reading..." # We know that the file contains text, so we read it using a stream reader. If the file content was # binary, you would process the stream according to the data format. try { [StreamReader]$streamReader = [IFileInfoExtension]::CreateStreamReader($fileInfo2) # Read in the text from the file and display it line by line. Write-Host Write-Host "Reading text lines:" $i = 0 while (-not $streamReader.EndOfStream) { $line = $streamReader.ReadLine() Write-Host "[$($i)] $($line)" $i++ } } finally { if ($streamReader -ne $null) { $streamReader.Dispose() } } } # Methods in the file provider model throw IOException and other exceptions, but not UAException. catch [Exception] { Write-Host "*** Failure: $($PSItem.Exception.GetBaseException().Message)" return } Write-Host Write-Host "Finished."
' Shows how to open a file stream for reading, and read its content using a text reader object, using OPC UA file provider model. ' ' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html . ' OPC client and subscriber examples in VB.NET on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-VBNET . ' Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own ' a commercial license in order to use Online Forums, and we reply to every post. Imports System.IO Imports OpcLabs.BaseLib.Extensions.FileProviders Imports OpcLabs.EasyOpc.UA Imports OpcLabs.EasyOpc.UA.FileTransfer Namespace FileProviders._FileInfo2 Friend Class ReadText Public Shared Sub Main1() ' Unified Automation .NET based demo server (UaNETServer/UaServerNET.exe) Dim endpointDescriptor As UAEndpointDescriptor = "opc.tcp://localhost:48030" ' A node that represents an instance of OPC UA FileType object. Dim fileNodeDescriptor As UANodeDescriptor = "nsu=http://www.unifiedautomation.com/DemoServer/ ;s=Demo.Files.TextFile" ' Instantiate the file transfer client object Dim fileTransferClient = New EasyUAFileTransferClient Console.WriteLine("Getting file info...") Dim fileInfo2 As IFileInfo2 = fileTransferClient.GetFileInfo2(endpointDescriptor, fileNodeDescriptor) ' From this point onwards, the code is independent of the concrete realization of the file provider, and would ' be identical e.g. for files in the physical file system, if the corresponding file provider was used. Try ' Get a stream reader object that corresponds to an OPC UA file. Console.WriteLine("Opening the file for reading...") ' We know that the file contains text, so we read it using a stream reader. If the file content was ' binary, you would process the stream according to the data format. Using streamReader As StreamReader = fileInfo2.CreateStreamReader() ' Read in the text from the file and display it line by line. Console.WriteLine() Console.WriteLine("Reading text lines:") Dim i As Integer = 0 While Not streamReader.EndOfStream Dim line As String = streamReader.ReadLine() Console.WriteLine($"[{i}] {line}") i += 1 End While End Using ' Methods in the file provider model throw IOException and other exceptions, but not UAException. Catch exception As Exception Console.WriteLine("*** Failure: {0}", exception.GetBaseException.Message) Exit Sub End Try Console.WriteLine() Console.WriteLine("Finished...") End Sub End Class End Namespace
# Shows how to open a file stream for reading, and read its content using a text reader object, using OPC UA file provider # model. # # Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html . # OPC client and subscriber examples in Python on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-Python . # Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own # a commercial license in order to use Online Forums, and we reply to every post. # The QuickOPC package is needed. Install it using "pip install opclabs_quickopc". import opclabs_quickopc # Import .NET namespaces. from System.IO import * from OpcLabs.BaseLib.Extensions.FileProviders import * from OpcLabs.EasyOpc.UA import * from OpcLabs.EasyOpc.UA.FileTransfer import * from OpcLabs.EasyOpc.UA.Navigation import * # Unified Automation .NET based demo server (UaNETServer/UaServerNET.exe). endpointDescriptor = UAEndpointDescriptor('opc.tcp://localhost:48030') # A node that represents an instance of OPC UA FileType object. fileNodeDescriptor = UANodeDescriptor('nsu=http://www.unifiedautomation.com/DemoServer/ ;s=Demo.Files.TextFile') # Instantiate the file transfer client object. fileTransferClient = EasyUAFileTransferClient() print('Getting file info......') fileInfo2 = IEasyUAFileTransferExtension.GetFileInfo2(fileTransferClient, endpointDescriptor, UANamedNodeDescriptor(fileNodeDescriptor)) # From this point onwards, the code is independent of the concrete realization of the file provider, and would # be identical e.g. for files in the physical file system, if the corresponding file provider was used. # Open the file, read two separate sections of it, and close it. streamReader = None try: # Get a stream reader object that corresponds to an OPC UA file. print('Opening the file for reading...') # We know that the file contains text, so we read it using a stream reader. If the file content was # binary, you would process the stream according to the data format. streamReader = IFileInfoExtension.CreateStreamReader(fileInfo2) # Read in the text from the file and display it line by line. print() print('Reading text lines...') i = 0 while not streamReader.EndOfStream: line = streamReader.ReadLine() print('[', i, '] ', line, sep='') i = i + 1 # Methods in the file provider model throw IOException and other exceptions, but not UAException. except Exception as exception: print('*** Failure: ' + exception.GetBaseException().Message) exit() finally: streamReader and streamReader.Dispose() print() print('Finished.')
Target Platforms: .NET Framework: Windows 10 (selected versions), Windows 11 (selected versions), Windows Server 2016, Windows Server 2022; .NET: Linux, macOS, Microsoft Windows
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