'Declaration
Sub Delete()
'Usage
Dim instance As IWritableFileInfo instance.Delete()
void Delete()
void Delete();
'Declaration
Sub Delete()
'Usage
Dim instance As IWritableFileInfo instance.Delete()
void Delete()
void Delete();
Exception | Description |
---|---|
System.ArgumentException | One of the arguments provided to a method is not valid. 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. |
System.ArgumentNullException |
A 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. |
System.IO.IOException | 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. |
System.NotSupportedException | An invoked method is not supported at all, or is not supported with the parameters used to create the object. |
System.Security.SecurityException | 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. |
System.UnauthorizedAccessException | 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. |
This method is similar in purpose to System.IO.FileInfo.Delete, but is generalized for any kind of writable file info, not just files in the physical file system.
If the file does not exist, this method does nothing. If you want an exception be thrown when the file does not exist, use the IWritableFileInfoExtension.DeleteExisting extension method.
// Shows how to create and delete OPC UA files, 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 OpcLabs.BaseLib.Extensions.FileProviders; using OpcLabs.EasyOpc.UA; using OpcLabs.EasyOpc.UA.Extensions; using OpcLabs.EasyOpc.UA.FileTransfer; namespace UADocExamples.FileProviders._WritableFileInfo { 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 files, and delete the first one. try { string fileName1 = "MyFile1-" + random.Next(); Console.WriteLine($"Creating first file, '{fileName1}'..."); IWritableFileInfo writableFileInfo1 = writableFileProvider.GetWritableFileInfo(fileName1); writableFileInfo1.WriteAllBytes(Array.Empty<byte>()); string fileName2 = "MyFile2-" + random.Next(); Console.WriteLine($"Creating second file, '{fileName2}'..."); IWritableFileInfo writableFileInfo2 = writableFileProvider.GetWritableFileInfo(fileName2); writableFileInfo2.WriteAllBytes(Array.Empty<byte>()); Console.WriteLine("Deleting the first file..."); writableFileInfo1.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..."); } } }
# Shows how to create and delete OPC UA files, 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 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 random # Import .NET namespaces. from System import * from OpcLabs.BaseLib.Extensions.FileProviders import * from OpcLabs.EasyOpc.UA import * from OpcLabs.EasyOpc.UA.Extensions import * from OpcLabs.EasyOpc.UA.FileTransfer import * # Unified Automation .NET based demo server (UaNETServer/UaServerNET.exe). endpointDescriptor = UAEndpointDescriptor('opc.tcp://localhost:48030') endpointDescriptor = UAEndpointDescriptorExtension.WithUserNameIdentity(endpointDescriptor,'john', 'master') # A node that represents an OPC UA file system (a root directory). fileSystemNodeDescriptor = UANodeDescriptor('nsu=http://www.unifiedautomation.com/DemoServer/ ;s=Demo.Files.FileSystem') # Create a random number generator - will be used for file/directory names. random = random.Random() # Instantiate the file transfer client object. fileTransferClient = EasyUAFileTransferClient() # Prevent prompt to trust the server certificate (INSECURE, used just for smooth example flow). EasyUAClient.SharedParameters.EngineParameters.CertificateAcceptancePolicy.TrustEndpointUrlString( endpointDescriptor.UrlString) print('Getting writable file provider...') writableFileProvider = IEasyUAFileTransferExtension.GetWritableFileProvider(fileTransferClient, 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 files, and delete the first one. try: fileName1 = 'MyFile1-' + str(random.randint(0, 999_999_999)) print("Creating first file, '", fileName1, "'...", sep='') writableFileInfo1 = writableFileProvider.GetWritableFileInfo(fileName1) IWritableFileInfoExtension.WriteAllBytes(writableFileInfo1, Array.Empty[Byte]()) fileName2 = 'MyFile2-' + str(random.randint(0, 999_999_999)) print("Creating second file, '", fileName2, "'...", sep='') writableFileInfo2 = writableFileProvider.GetWritableFileInfo(fileName2) IWritableFileInfoExtension.WriteAllBytes(writableFileInfo2, Array.Empty[Byte]()) print('Deleting the first file...') writableFileInfo1.Delete() # Methods in the file provider model throw IOException and other exceptions, but not UAException. except Exception as exception: print('*** Failure: ' + exception.GetBaseException().Message) exit() print() print('Finished.')
' Shows how to create and delete OPC UA files, using the file provider model. ' ' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html . Imports OpcLabs.BaseLib.Extensions.FileProviders Imports OpcLabs.EasyOpc.UA Imports OpcLabs.EasyOpc.UA.Extensions Imports OpcLabs.EasyOpc.UA.FileTransfer Namespace FileProviders._WritableFileInfo Friend Class CreateAndDelete Public Shared Sub Main1() ' Unified Automation .NET based demo server (UaNETServer/UaServerNET.exe) Dim endpointDescriptor As UAEndpointDescriptor = New UAEndpointDescriptor("opc.tcp://localhost:48030") _ .WithUserNameIdentity("john", "master") ' A node that represents an OPC UA file system (a root directory). Dim fileSystemNodeDescriptor As UANodeDescriptor = "nsu=http://www.unifiedautomation.com/DemoServer/ ;s=Demo.Files.FileSystem" ' Create a random number generator - will be used for file/directory names. Dim random = New Random ' Instantiate the file transfer client object Dim fileTransferClient = New EasyUAFileTransferClient Console.WriteLine("Getting writable file provider...") Dim writableFileProvider As IWritableFileProvider = 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 files, and delete the first one. Try Dim fileName1 As String = "MyFile1-" & random.Next() Console.WriteLine($"Creating first file, '{fileName1}'...") Dim writableFileInfo1 As IWritableFileInfo = writableFileProvider.GetWritableFileInfo(fileName1) writableFileInfo1.WriteAllBytes(Array.Empty(Of Byte)) Dim fileName2 As String = "MyFile2-" & random.Next() Console.WriteLine($"Creating second file, '{fileName2}'...") Dim writableFileInfo2 As IWritableFileInfo = writableFileProvider.GetWritableFileInfo(fileName2) writableFileInfo2.WriteAllBytes(Array.Empty(Of Byte)) Console.WriteLine("Deleting the first file...") writableFileInfo1.Delete() ' 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("Finished...") End Sub End Class End Namespace