<TypeConverter(GetType(EnumNameFormatterConverter))>
Public Enum TestEnum
    MyUpperCamelCaseName
    myLowerCamelCaseName
    My_Upper_Snake_Case_Name
    my_lower_snake_case_name
 
    MyMixed_value123_WTF456wtf_
 
    ___rare_case_STRANGE_Name___________123_aZ_Az_4_5_6_
End Enum

<DefaultValue(TestEnum.MyUpperCamelCaseName)>
Public Property Test As TestEnum = TestEnum.MyUpperCamelCaseName

Imports System.ComponentModel
Imports System.Globalization
Imports System.Runtime.InteropServices
Imports System.Text
 
''' <summary>
''' Provides conversion functionality between the value names of an <see cref="[Enum]"/> to a friendly string representation.
''' <para></para>
''' This converter is optimized for enum names written in either upper/lower snake case or upper/lower camel case:
''' <list type="bullet">
'''     <item><description>Snake case: Each word is separated by underscores (e.g.: "My_Value").</description></item>
'''     <item><description>Camel case: Each word is separated by a capitalized letter (e.g.: "MyValue").</description></item>
''' </list>
''' </summary>
Public NotInheritable Class EnumNameFormatterConverter : Inherits EnumConverter
 
    ''' <summary>
    ''' Initializes a new instance of the <see cref="EnumNameFormatterConverter"/> class.
    ''' </summary>
    ''' <param name="type">A <see cref="T:System.Type" /> that represents the type of enumeration to associate with this enumeration converter.</param>
    Public Sub New(type As Type)
        MyBase.New(type)
    End Sub
 
    ''' <summary>
    ''' Returns whether this converter can convert an object of the given type to the type of this converter, 
    ''' using the specified context.
    ''' </summary>
    ''' 
    ''' <param name="context">
    ''' An <see cref="ITypeDescriptorContext"/> that provides a format context.
    ''' </param>
    ''' 
    ''' <param name="sourceType">
    ''' A <see cref="Type" /> that represents the type you want to convert from.
    ''' </param>
    ''' 
    ''' <returns>
    ''' <see langword="True"/> if this converter can perform the conversion; otherwise, <see langword="False"/>.
    ''' </returns>
    Public Overrides Function CanConvertFrom(context As ITypeDescriptorContext, sourceType As Type) As Boolean
 
        Return sourceType Is GetType(String) OrElse
               MyBase.CanConvertFrom(context, sourceType)
 
    End Function
 
    ''' <summary>
    ''' Returns whether this converter can convert the object to the specified type, using the specified context.
    ''' </summary>
    ''' 
    ''' <param name="context">
    ''' An <see cref="ITypeDescriptorContext"/> that provides a format context.
    ''' </param>
    ''' 
    ''' <param name="destinationType">
    ''' A <see cref="Type"/> that represents the type you want to convert to.
    ''' </param>
    ''' 
    ''' <returns>
    ''' <see langword="True"/> if this converter can perform the conversion; otherwise, <see langword="False"/>.
    ''' </returns>
    Public Overrides Function CanConvertTo(context As ITypeDescriptorContext, destinationType As Type) As Boolean
 
        Return destinationType Is GetType(String) OrElse
               MyBase.CanConvertTo(context, destinationType)
 
    End Function
 
    ''' <summary>
    ''' Converts the given object to the type of this converter, using the specified context and culture information.
    ''' </summary>
    ''' 
    ''' <param name="context">
    ''' An <see cref="ITypeDescriptorContext"/> that provides a format context.
    ''' </param>
    ''' 
    ''' <param name="culture">
    ''' The <see cref="CultureInfo"/> to use as the current culture.
    ''' </param>
    ''' 
    ''' <param name="value">
    ''' The <see cref="Object"/> to convert.
    ''' </param>
    ''' 
    ''' <returns>
    ''' An <see cref="Object"/> that represents the converted value.
    ''' </returns>
    <DebuggerStepThrough>
    Public Overrides Function ConvertFrom(context As ITypeDescriptorContext, culture As CultureInfo, value As Object) As Object
 
        If TypeOf value Is String Then
            value = DirectCast(value, String).Replace(" ", "").Replace(Convert.ToChar(&H205F), "_"c)
            Return [Enum].Parse(Me.EnumType, value, ignoreCase:=True)
        End If
 
        Return MyBase.ConvertFrom(context, culture, value)
 
    End Function
 
    ''' <summary>
    ''' Converts the given value object to the specified type, using the specified context and culture information.
    ''' </summary>
    ''' 
    ''' <param name="context">
    ''' An <see cref="ITypeDescriptorContext"/> that provides a format context.
    ''' </param>
    ''' 
    ''' <param name="culture">
    ''' A <see cref="CultureInfo"/>. If null is passed, the current culture is assumed.
    ''' </param>
    ''' 
    ''' <param name="value">
    ''' The <see cref="Object"/> to convert.
    ''' </param>
    ''' 
    ''' <param name="destinationType">
    ''' The <see cref="Type"/> to convert the <paramref name="value"/> parameter to.
    ''' </param>
    ''' 
    ''' <returns>
    ''' An <see cref="Object"/> that represents the converted value.
    ''' </returns>
    <DebuggerStepThrough>
    Public Overrides Function ConvertTo(context As ITypeDescriptorContext, culture As CultureInfo, value As Object, destinationType As Type) As Object
 
        If destinationType = GetType(String) Then
            Dim name As String = [Enum].GetName(value.GetType(), value)
            If Not String.IsNullOrEmpty(name) Then
                Return Me.FormatName(name)
            End If
        End If
 
        Return MyBase.ConvertTo(context, culture, value, destinationType)
 
    End Function
 
    ''' <summary>
    ''' Formats the name of a <see cref="[Enum]"/> value to a friendly name.
    ''' </summary>
    ''' 
    ''' <param name="name">
    ''' <see cref="[Enum]"/> value name.
    ''' </param>
    ''' 
    ''' <returns>
    ''' The resulting friendly name.
    ''' </returns>
    <DebuggerStepThrough>
    Private Function FormatName(name As String) As String
        Dim sb As New StringBuilder()
        Dim previousChar As Char
        Dim previousCharIsWhiteSpace As Boolean
        Dim previousCharIsUpperLetter As Boolean
        Dim previousCharIsDigit As Boolean
        Dim lastParsedCharIsUnderscore As Boolean
        Dim firstCapitalizedLetterIsAdded As Boolean
 
        For i As Integer = 0 To name.Length - 1
            Dim c As Char = name(i)
            If i = 0 Then
                If c.Equals("_"c) Then
                    sb.Append(Convert.ToChar(Convert.ToChar(&H205F)))
                    lastParsedCharIsUnderscore = True
                Else
                    sb.Append(Char.ToUpper(c))
                    firstCapitalizedLetterIsAdded = True
                End If
                Continue For
            End If
 
            previousChar = sb.Chars(sb.Length - 1)
            previousCharIsWhiteSpace = previousChar.Equals(" "c) OrElse previousChar.Equals(Convert.ToChar(&H205F))
            previousCharIsUpperLetter = Char.IsUpper(previousChar)
            previousCharIsDigit = Char.IsDigit(previousChar)
 
            If Char.IsLetter(c) Then
                If previousCharIsDigit AndAlso Not previousCharIsWhiteSpace Then
                    sb.Append(" "c)
                End If
 
                If Char.IsUpper(c) Then
                    If previousCharIsUpperLetter Then
                        sb.Append(c)
                    ElseIf Not previousCharIsWhiteSpace Then
                        sb.Append(" "c)
                        sb.Append(c)
                    Else
                        sb.Append(c)
                    End If
                    firstCapitalizedLetterIsAdded = True
 
                Else
                    If Not firstCapitalizedLetterIsAdded Then
                        sb.Append(Char.ToUpper(c))
                        firstCapitalizedLetterIsAdded = True
                    Else
                        sb.Append(c)
                    End If
 
                End If
 
            ElseIf Char.IsDigit(c) Then
                If Not previousCharIsDigit AndAlso Not previousCharIsWhiteSpace Then
                    sb.Append(" "c)
                End If
                sb.Append(c)
 
            ElseIf c.Equals("_"c) Then
                If lastParsedCharIsUnderscore OrElse Not previousCharIsWhiteSpace Then
                    sb.Append(Convert.ToChar(&H205F)) ' Unicode white-space: "&#8195;"
                    lastParsedCharIsUnderscore = True
                End If
 
            Else
                sb.Append(c)
                lastParsedCharIsUnderscore = False
 
            End If
 
        Next i
 
        Return sb.ToString()
    End Function
 
End Class
 

• DllExport de 3F
• UnmanagedExports de Huajitech
• UnmanagedExports.Repack.Upgrade de StevenEngland

' ***********************************************************************
' Author   : ElektroStudios
' Modified : 16-January-2025
' ***********************************************************************
 
#Region " Option Statements "
 
Option Strict On
Option Explicit On
Option Infer Off
 
#End Region
 
#Region " Usage Examples "
 
' VB.NET
' <DllExport(NameOf(MyStringFunction), CallingConvention.StdCall)>
' Public Shared Function MyStringFunction() As <MarshalAs(UnmanagedType.BStr)> String
'     Return "Hello World!"
' End Function
 
' C#
' [DllExport(nameof(MyStringFunction), CallingConvention.StdCall)]
' [return: MarshalAs(UnmanagedType.BStr)]
' public static string MyStringFunction() {
'     return "Hello World!";
' }
 
#End Region
 
#Region " Imports "
 
Imports System.Runtime.InteropServices
 
#End Region
 
' ReSharper disable once CheckNamespace
 
#Region " DllExportAttribute "
 
Namespace DevCase.Runtime.Attributes
 
    ''' <summary>
    ''' The <see cref="DllExportAttribute"/> class indicates that a method can be 
    ''' exported as a C function from a .NET dynamic-link library (DLL) file, 
    ''' making the method callable from unmanaged code.
    ''' <para></para>
    ''' The <see cref="DllExportAttribute"/> class is solely intended to replicate and improve the 
    ''' <b>DllExportAttribute</b> attribute class from plugins like:
    ''' <list type="bullet">
    '''   <item><b>DllExport</b> by 3F
    '''     <para></para> 
    '''     <see href="https://github.com/3F/DllExport"/>
    '''   </item>
    '''   
    '''   <item><b>UnmanagedExports</b> by Huajitech
    '''     <para></para>
    '''     <see href="https://github.com/huajitech/UnmanagedExports"/>
    '''   </item>
    '''   
    '''   <item><b>UnmanagedExports.Repack.Upgrade</b> by StevenEngland
    '''     <para></para>
    '''     <see href="https://github.com/stevenengland/UnmanagedExports.Repack.Upgrade"/>
    '''   </item>
    ''' </list>
    ''' Allowing a programmer to use this attribute class without having the plugin installed in their Visual Studio projects.
    ''' <para></para>
    ''' Be aware that it is still necessary to use one of the mentioned projects to enable .NET functions export.
    ''' </summary>
    <AttributeUsage(AttributeTargets.Method, AllowMultiple:=False, Inherited:=False)>
    Public NotInheritable Class DllExportAttribute : Inherits Attribute
 
#Region " Properties "
 
        ''' <summary>
        ''' Gets or sets the calling convention required to call this C-exported function from unmanaged code.
        ''' <para></para>
        ''' Default value is <see cref="System.Runtime.InteropServices.CallingConvention.Cdecl"/>,
        ''' like for other C/C++ programs (Microsoft Specific).
        ''' <para></para>
        ''' Value <see cref="System.Runtime.InteropServices.CallingConvention.StdCall"/> is mostly used with Windows API.
        ''' <para></para>
        ''' </summary>
        Public Property CallingConvention As CallingConvention = CallingConvention.Cdecl
 
        ''' <summary>
        ''' Gets or sets the optional name for this C-exported function.
        ''' </summary>
        ''' <remarks>
        ''' See also:
        ''' <seealso href="https://learn.microsoft.com/en-us/cpp/build/reference/decorated-names?view=msvc-170#FormatC">
        ''' Format of a C decorated name.
        ''' </seealso>
        ''' </remarks>
        Public Property ExportName As String
 
#End Region
 
#Region " Constructors "
 
        ''' <summary>
        ''' Initializes a new instance of the <see cref="DllExportAttribute"/> class.
        ''' <para></para>
        ''' Use this constructor only if you plan to use <b>DllExport</b> by 3F (<see href="https://github.com/3F/DllExport"/>),
        ''' <para></para>
        ''' otherwise, use <see cref="DllExportAttribute.New(String, CallingConvention)"/> 
        ''' to specify the export name and calling convention.
        ''' </summary>
        ''' 
        ''' <param name="convention">
        ''' The calling convention required to call this C-exported function.
        ''' <para></para>
        ''' Default value is <see cref="System.Runtime.InteropServices.CallingConvention.Cdecl"/>,
        ''' like for other C/C++ programs (Microsoft Specific).
        ''' <para></para>
        ''' Value <see cref="System.Runtime.InteropServices.CallingConvention.StdCall"/> is mostly used with Windows API.
        ''' <para></para>
        ''' </param>
        ''' 
        ''' <param name="exportName">
        ''' The optional name for this C-exported function.
        ''' See also: 
        ''' <seealso href="https://learn.microsoft.com/en-us/cpp/build/reference/decorated-names?view=msvc-170#FormatC">
        ''' Format of a C decorated name.
        ''' </seealso>
        ''' </param>
        Public Sub New(convention As CallingConvention, exportName As String)
 
            Me.CallingConvention = convention
            Me.ExportName = exportName
        End Sub
 
        ''' <summary>
        ''' Initializes a new instance of the <see cref="DllExportAttribute"/> class.
        ''' <para></para>
        ''' Do not use this constructor if you plan to use <b>DllExport</b> by 3F (<see href="https://github.com/3F/DllExport"/>),
        ''' <para></para>
        ''' in that case use <see cref="DllExportAttribute.New(CallingConvention, String)"/>  
        ''' to specify the export name and calling convention.
        ''' </summary>
        ''' 
        ''' <param name="exportName">
        ''' The optional name for this C-exported function.
        ''' See also: 
        ''' <seealso href="https://learn.microsoft.com/en-us/cpp/build/reference/decorated-names?view=msvc-170#FormatC">
        ''' Format of a C decorated name.
        ''' </seealso>
        ''' </param>
        ''' 
        ''' <param name="convention">
        ''' The calling convention required to call this C-exported function.
        ''' <para></para>
        ''' Default value is <see cref="System.Runtime.InteropServices.CallingConvention.Cdecl"/>,
        ''' like for other C/C++ programs (Microsoft Specific).
        ''' <para></para>
        ''' Value <see cref="System.Runtime.InteropServices.CallingConvention.StdCall"/> is mostly used with Windows API.
        ''' <para></para>
        ''' </param>
        Public Sub New(exportName As String, convention As CallingConvention)
 
            Me.ExportName = exportName
            Me.CallingConvention = convention
        End Sub
 
        ''' <summary>
        ''' Initializes a new instance of the <see cref="DllExportAttribute"/> class.
        ''' </summary>
        ''' 
        ''' <param name="exportName">
        ''' The optional name for this C-exported function.
        ''' See also: 
        ''' <seealso href="https://learn.microsoft.com/en-us/cpp/build/reference/decorated-names?view=msvc-170#FormatC">
        ''' Format of a C decorated name.
        ''' </seealso>
        ''' </param>
        Public Sub New(exportName As String)
 
            Me.New(exportName, CallingConvention.Cdecl)
        End Sub
 
        ''' <summary>
        ''' Initializes a new instance of the <see cref="DllExportAttribute"/> class.
        ''' </summary>
        ''' 
        ''' <param name="convention">
        ''' The calling convention required to call this C-exported function.
        ''' <para></para>
        ''' Default value is <see cref="System.Runtime.InteropServices.CallingConvention.Cdecl"/>,
        ''' like for other C/C++ programs (Microsoft Specific).
        ''' <para></para>
        ''' Value <see cref="System.Runtime.InteropServices.CallingConvention.StdCall"/> is mostly used with Windows API.
        ''' <para></para>
        ''' </param>
        Public Sub New(convention As CallingConvention)
 
            Me.New(String.Empty, convention)
        End Sub
 
        ''' <summary>
        ''' Initializes a new instance of the <see cref="DllExportAttribute"/> class.
        ''' </summary>
        Public Sub New()
        End Sub
 
#End Region
 
    End Class
 
#End Region
 
End Namespace

<DllExport(NameOf(MyStringFunction), CallingConvention.StdCall)>
Public Shared Function MyStringFunction() As <MarshalAs(UnmanagedType.BStr)> String
    Return "Hello World!"
End Function

[DllExport(nameof(MyStringFunction), CallingConvention.StdCall)]
[return: MarshalAs(UnmanagedType.BStr)]
public static string MyStringFunction() {
    return "Hello World!";
}

function MyStringFunction(): Cardinal;
  external 'MyStringFunction@files:MyNetAPI.dll stdcall';