• 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';