OPC Studio User's Guide and Reference
Delete Method (IWritableDirectoryContents)
Example 



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OpcLabs.BaseLib Assembly > OpcLabs.BaseLib.Extensions.FileProviders Namespace > IWritableDirectoryContents Interface : Delete Method
true to delete this directory, its subdirectories, and all files; false to delete just this directory.
Deletes a directory represented by this IWritableDirectoryContents, specifying whether to delete subdirectories and files.
Syntax
'Declaration
 
Sub Delete( _
   ByVal recursive As Boolean _
) 
 
'Usage
 
Dim instance As IWritableDirectoryContents
Dim recursive As Boolean
 
instance.Delete(recursive)

Parameters

recursive
true to delete this directory, its subdirectories, and all files; false to delete just this directory.
Exceptions
ExceptionDescription

Part of a file or directory cannot be found.

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 , but is generalized for a file provider model and thus an abstract file system.

If the IWritableDirectoryContents has no files or subdirectories, this method deletes the directory even if recursive is false. Attempting to delete a directory that is not empty when recursive is false throws an System.IO.IOException.

Example
// Shows how to create and delete OPC UA directories, using the 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 OpcLabs.BaseLib.Extensions.FileProviders;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.Extensions;
using OpcLabs.EasyOpc.UA.FileTransfer;

namespace UADocExamples.FileProviders._WritableDirectoryContents
{
    class CreateAndDelete
    {
        public static void Main1()
        {
            // Unified Automation .NET based demo server (UaNETServer/UaServerNET.exe)
            var endpointDescriptor = new UAEndpointDescriptor("opc.tcp://localhost:48030")
                .WithUserNameIdentity("john", "master");

            // A node that represents an OPC UA file system (a root directory).
            UANodeDescriptor fileSystemNodeDescriptor = "nsu=http://www.unifiedautomation.com/DemoServer/ ;s=Demo.Files.FileSystem";

            // Create a random number generator - will be used for file/directory names.
            var random = new Random();
            
            // Instantiate the file transfer client object
            var fileTransferClient = new EasyUAFileTransferClient();

            Console.WriteLine("Getting writable file provider...");
            IWritableFileProvider writableFileProvider =
                fileTransferClient.GetWritableFileProvider(endpointDescriptor, fileSystemNodeDescriptor);
            // 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.

            // Create two directories, and one nested directory, and delete the first one.
            try
            {
                string directoryName1 = "MyDirectory1-" + random.Next();
                Console.WriteLine($"Creating first directory, '{directoryName1}'...");
                IWritableDirectoryContents writableDirectoryContents1 = writableFileProvider.GetWritableDirectoryContents(directoryName1);
                writableDirectoryContents1.Create();

                string directoryName2 = "MyDirectory2-" + random.Next();
                Console.WriteLine($"Creating second directory, '{directoryName2}'...");
                IWritableDirectoryContents writableDirectoryContents2 = writableFileProvider.GetWritableDirectoryContents(directoryName2);
                writableDirectoryContents2.Create();

                string nestedDirectoryName = "MyDirectory3-" + random.Next();
                Console.WriteLine($"Creating nested directory, '{nestedDirectoryName}'...");
                writableDirectoryContents2.CreateSubdirectory(nestedDirectoryName);

                // At this moment, the directory structure we have created looks like this:
                // * MyDirectory1
                // * MyDirectory2
                // * * MyDirectory3

                Console.WriteLine("Deleting the first directory...");
                writableDirectoryContents1.Delete();
            }
            // 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("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

Reference

IWritableDirectoryContents Interface
IWritableDirectoryContents Members
Create Method
OpcLabs.BaseLib.Extensions.FileProviders.IWritableDirectoryContentsExtension.Delete(OpcLabs.BaseLib.Extensions.FileProviders.IWritableDirectoryContents)