OPC Studio User's Guide and Reference
ReadAllBytes(IFileInfo) Method
Example 



View with Navigation Tools
OpcLabs.BaseLib Assembly > OpcLabs.BaseLib.Extensions.FileProviders Namespace > IFileInfoExtension Class > ReadAllBytes Method : ReadAllBytes(IFileInfo) Method
A file info that represents a file in the file provider.
Returns the contents of a file in an abstract file provider as a byte array.
Syntax
'Declaration
 
<ExtensionAttribute()>
<NotNullAttribute()>
Public Overloads Shared Function ReadAllBytes( _
   ByVal fileInfo As IFileInfo _
) As Byte()
 
'Usage
 
Dim fileInfo As IFileInfo
Dim value() As Byte
 
value = IFileInfoExtension.ReadAllBytes(fileInfo)

Parameters

fileInfo
A file info that represents a file in the file provider.

Return Value

System.Byte array containing the contents of the file.
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.

An attempt to access a file that does not exist on disk has failed.

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.

An I/O error has occurred.

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.

An invoked method is not supported at all, or is not supported with the parameters used to create the object.

A security error was detected.

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.

The operating system has denied access because of an I/O error or a specific type of security error.

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 method is similar to FileSystem.ReadAllBytes Method for normal (operating system) files.

This method allows you to read from a binary file. The contents of the file are returned as a byte array.

Example

.NET

// Shows how to read the full contents of an OPC UA file at once, using the file provider model.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

using System;
using System.Text;
using OpcLabs.BaseLib.Extensions.FileProviders;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.FileTransfer;

namespace UADocExamples.FileProviders._FileInfo2
{
    class ReadAllBytes
    {
        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.

            // Read in all contents from a specified file node.
            byte[] bytes;
            try
            {
                Console.WriteLine("Reading the whole file...");
                bytes = fileInfo2.ReadAllBytes();
            }
            // Methods in the file provider model throw IOException and other exceptions, but not UAException.
            catch (Exception exception)
            {
                Console.WriteLine($"*** Failure: {exception.GetBaseException().Message}");
                return;
            }

            // Display result
            Console.WriteLine();
            // We know that the file contains text, so we convert the received data to a string. If the file contents was
            // binary, you would process the data according to their format.
            string text = Encoding.UTF8.GetString(bytes);
            Console.WriteLine("File content:");
            Console.WriteLine(text);

            Console.WriteLine();
            Console.WriteLine("Finished...");
        }
    }
}
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