OPC Studio User's Guide and Reference
GetFileInfo2 Method (MappedFileProvider)
Example 



OpcLabs.BaseLib Assembly > OpcLabs.BaseLib.Extensions.FileProviders Namespace > MappedFileProvider Class : GetFileInfo2 Method
Relative path that identifies the file.
Obtain a file info at the given path.
Syntax
'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)
public IFileInfo2 GetFileInfo2( 
   string subpath
)
public:
IFileInfo2^ GetFileInfo2( 
   String^ subpath
) 

Parameters

subpath
Relative path that identifies the file.

Return Value

The file information. Caller must check property.
Remarks

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.

Example

.NET

// 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 .

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 .

#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 Python on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-Python .
# 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.')
' 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 .

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
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