' https://stackoverflow.com/questions/65507185/how-to-return-funcof-t-ienumerableof-t-inside-a-function-which-handles-the

' https://stackoverflow.com/questions/65443704/how-to-make-my-vb-net-code-dynamic-instead-of-static

Imports System

Imports System.Linq

Imports System.Collections.Generic

Imports System.IO

Imports Microsoft.VisualBasic

Imports System.Security.AccessControl

​

Imports Newtonsoft.Json

Imports Newtonsoft.Json.Linq

Imports Newtonsoft.Json.Converters

Imports Newtonsoft.Json.Serialization

​

Imports NUnit.Framework

​

    ' https://stackoverflow.com/questions/65507185/how-to-return-funcof-t-ienumerableof-t-inside-a-function-which-handles-the

    ' https://stackoverflow.com/questions/65443704/how-to-make-my-vb-net-code-dynamic-instead-of-static

​

Public Class DirectoryExtensions

    Shared Function GetFileSystemAccessRules(d As DirectoryInfo, ByVal errorHandler As Action(Of Object, DirectoryTraversalErrorEventArgs)) As IEnumerable(Of FileSystemAccessRule)

        Try

            Dim ds As DirectorySecurity = d.GetAccessControl()

            Dim arrRules As AuthorizationRuleCollection = ds.GetAccessRules(True, True, GetType(Security.Principal.NTAccount))

            Return arrRules.Cast(Of FileSystemAccessRule)()

        Catch ex As Exception

            If (Not HandleError(errorHandler, d.FullName, ex))

                Throw

            End If

            Return Enumerable.Empty(Of FileSystemAccessRule)()

        End Try

    End Function

    Shared Function EnumerateDirectories(ByVal directory As String, ByVal errorHandler As Action(Of Object, DirectoryTraversalErrorEventArgs)) As IEnumerable(Of DirectoryInfo)

        Dim di As DirectoryInfo

        Try

            di = new DirectoryInfo(directory)

        Catch ex As Exception

            If (Not HandleError(errorHandler, directory, ex))

                Throw

            End If

            Return Enumerable.Empty(Of DirectoryInfo)()

        End Try

        ' In .NET Core 2.1+ it should be able to recursively enumerate directories and ignore errors as follows:

        ' Dim query = { di }.Concat(di.EnumerateDirectories("*", New System.IO.EnumerationOptions With { .RecurseSubdirectories = True, .IgnoreInaccessible = True })))

        ' In the meantime, it's necessary to manually catch and ignore errors.

        Dim query = RecursiveEnumerableExtensions.Traverse(di, 

            Function(d)

                Try

                    Return d.GetDirectories()

                Catch ex As Exception

                    If (Not HandleError(errorHandler, d.FullName, ex))

                        Throw

                    End If

                    Return Enumerable.Empty(Of DirectoryInfo)()

                End Try

            End Function

        )

        Return query

    End Function

​

    Shared Function EnumerateDirectoryFileSystemAccessRules(ByVal directory As String, ByVal errorHandler As Action(Of Object, DirectoryTraversalErrorEventArgs)) As IEnumerable(Of Tuple(Of DirectoryInfo, IEnumerable(Of FileSystemAccessRule)))

        Return EnumerateDirectories(directory, errorHandler).Select(Function(d) Tuple.Create(d, GetFileSystemAccessRules(d, errorHandler)))

    End Function

    Shared Public Function SerializeFileAccessRules(ByVal directory As String, ByVal errorHandler As Action(Of Object, DirectoryTraversalErrorEventArgs), Optional ByVal formatting As Formatting = Formatting.Indented)

        Dim query = EnumerateDirectoryFileSystemAccessRules(directory, errorHandler).Select(

            Function(tuple) New With {

                .directory = tuple.Item1.FullName,

                .permissions = tuple.Item2.Select(

                    Function(a) New With { 

                        .IdentityReference = a.IdentityReference.ToString(),

                        .AccessControlType = a.AccessControlType.ToString(),

                        .FileSystemRights = a.FileSystemRights.ToString(),

                        .IsInherited = a.IsInherited.ToString()

                    }

                )

            }

        )

        Return JsonConvert.SerializeObject(query, formatting)   

    End Function

    Private Shared Function HandleError(ByVal errorHandler As Action(Of Object, DirectoryTraversalErrorEventArgs), ByVal fullName as String, ByVal ex as Exception) As Boolean

        If (errorHandler Is Nothing)

            Return False

        End If

        Dim args As New DirectoryTraversalErrorEventArgs(fullName, ex)

        errorHandler(GetType(DirectoryExtensions), args)

        return args.Handled

    End Function                                

End Class

​

Public Class DirectoryTraversalErrorEventArgs 

    Inherits EventArgs

    Private _directory As String

    Private _exception As Exception

​

    Public Sub New(ByVal directory as String, ByVal exception as Exception)

        Me._directory = directory

        Me._exception = exception

    End Sub

    Public Property Handled As Boolean = false

    Public Readonly Property Directory As String

        Get

            Return _directory

        End Get

    End Property

    Public Readonly Property Exception As Exception

        Get

            Return _exception

        End Get

    End Property

End Class

​

Public Module RecursiveEnumerableExtensions

    ' Translated to vb.net from this answer https://stackoverflow.com/a/60997251/3744182

    ' To https://stackoverflow.com/questions/60994574/how-to-extract-all-values-for-all-jsonproperty-objects-with-a-specified-name-fro

    ' which was rewritten from the answer by Eric Lippert https://stackoverflow.com/users/88656/eric-lippert

    ' to "Efficient graph traversal with LINQ - eliminating recursion" https://stackoverflow.com/questions/10253161/efficient-graph-traversal-with-linq-eliminating-recursion

    Iterator Function Traverse(Of T)(ByVal root As T, ByVal children As Func(Of T, IEnumerable(Of T)), ByVal Optional includeSelf As Boolean = True) As IEnumerable(Of T)

        If includeSelf Then Yield root

        Dim stack = New Stack(Of IEnumerator(Of T))()

​

        Try

            stack.Push(children(root).GetEnumerator())

            While stack.Count <> 0

                Dim enumerator = stack.Peek()

                If Not enumerator.MoveNext() Then

                    stack.Pop()

                    enumerator.Dispose()

                Else

                    Yield enumerator.Current

                    stack.Push(children(enumerator.Current).GetEnumerator())

                End If

            End While

        Finally

            For Each enumerator In stack

                enumerator.Dispose()

            Next

        End Try

    End Function

End Module

​

Public Module TestClass

    Friend Sub Test()

        'Dim str_rootdirectory As String = Directory.GetCurrentDirectory() ' "C:\TEMP"

        Test(Directory.GetCurrentDirectory())

    End Sub

​

    Friend Sub Test(ByVal curDirectory As String)

        Console.WriteLine()

        Console.WriteLine("Testing directory {0}", curDirectory)

        Dim errors = New List(Of Tuple(Of String, String))

        Dim handler As Action(Of Object, DirectoryTraversalErrorEventArgs) = 

            Sub(sender, e)

                errors.Add(Tuple.Create(e.Directory, e.Exception.Message))

                e.Handled = true

            End Sub

        Dim json As String = DirectoryExtensions.SerializeFileAccessRules(curDirectory, handler) 

        ' Output the JSON and the errors somehow

        Console.WriteLine(json)

        For Each e In errors

            Console.WriteLine("Error in directory {0}: {1}", e.Item1, e.Item2)

        Next

        File.WriteAllText("ABCD.json", json)

    End Sub

End Module

​

Public Module Module1   

    Public Sub Main()

        Console.WriteLine("Environment version: " & Environment.Version.ToString())

        Console.WriteLine("Json.NET version: " & GetType(JsonSerializer).Assembly.FullName)

        Console.WriteLine("")

​

        Try

            Directory.CreateDirectory("SubDirectory")

            TestClass.Test()

            TestClass.Test("C:\TEMP")

​

        Catch ex as Exception

            Console.WriteLine("Unhandled exception: ")

            Console.WriteLine(ex)

            Throw

        End Try

    End Sub 

End Module

' It's not clear where your problem is exactly because you don't share a [mcve], e.g. you don't show how `arrRules` is determined.  But is this what you want?  https://dotnetfiddle.net/zTd3tW  The code here enumerates through a directory hierarchy and, for each `DirectoryInfo`, enumerates through its `FileSystemAccessRule` objects and projects the result to a dictionary.  note that the code won't run on https://dotnetfiddle.net/ because of security permission issues.                         

' @BakuBakar - Please give the full `ToString()` output of the exception including the exception type, message, traceback and inner exception(s) if any. I am not currently running inside an IDE I am on holiday and using https://dotnetfiddle.net/.  And what exactly is the problem?  Is it that an exception is being thrown that should be caught, or that an exception is bring caught and handled when there should not be any exception at all?  Your question was about how to continue after an error, nor avoid the error entirely, so if it's the latter please provide a [mcve] or ask another question.