Imports System
Imports System.Runtime.InteropServices
Imports System.Reflection

Class LCIDAttrSampler

    Const LCID_INSTALLED As Integer = 1
    Const LCID_SUPPORTED As Integer = 2

    <DllImport("KERNEL32.DLL", EntryPoint:="IsValidLocale", _
    SetLastError:=True, CharSet:=CharSet.Unicode, _
    CallingConvention:=CallingConvention.StdCall), _
    LCIDConversionAttribute(0)> _
    Public Shared Function IsValidLocale(ByVal dwFlags As Integer) As Boolean
    End Function

    Public Sub CheckCurrentLCID()
        Dim mthIfo As MethodInfo = Me.GetType().GetMethod("IsValidLocale")
        Dim attr As Attribute = Attribute.GetCustomAttribute(mthIfo, GetType(LCIDConversionAttribute))

        If Not(attr Is Nothing) Then
            Dim lcidAttr As LCIDConversionAttribute = CType(attr, LCIDConversionAttribute)
            Console.WriteLine("Position of the LCID argument in the unmanaged signature: " + lcidAttr.Value.ToString())
        End If

        Dim res As Boolean = IsValidLocale(LCID_INSTALLED)
        Console.WriteLine("Result LCID_INSTALLED " + res.ToString())
        res = IsValidLocale(LCID_SUPPORTED)
        Console.WriteLine("Result LCID_SUPPORTED " + res.ToString())
    End Sub

    Public Shared Sub Main()
        Dim smpl As LCIDAttrSampler = New LCIDAttrSampler()
        smpl.CheckCurrentLCID()
    End Sub

End Class

    using System;
    using System.Runtime.InteropServices;
    using System.Reflection;

    class LCIDAttrSample
    {
        private const int LCID_INSTALLED = 1;
        private const int LCID_SUPPORTED = 2;

        [DllImport("KERNEL32.DLL", EntryPoint="IsValidLocale", SetLastError = true, CharSet = CharSet.Auto)]
        [LCIDConversionAttribute(0)] // Position of the LCID argument
        public static extern bool IsValidLocale(
                                                    uint dwFlags            // options
                                                );

        public void CheckCurrentLCID()
        {
            MethodInfo mthIfo = this.GetType().GetMethod("IsValidLocale");
            Attribute attr = Attribute.GetCustomAttribute(mthIfo,typeof(LCIDConversionAttribute));

            if( attr != null)
            {
                LCIDConversionAttribute lcidAttr = (LCIDConversionAttribute)attr;
                Console.WriteLine("Position of the LCID argument in the unmanaged signature: " + lcidAttr.Value.ToString());
            }

            bool res = IsValidLocale(LCID_INSTALLED);
            Console.WriteLine("Result LCID_INSTALLED " + res.ToString());
            res = IsValidLocale(LCID_SUPPORTED);
            Console.WriteLine("Result LCID_SUPPORTED " + res.ToString());
        }

        static void Main(string[] args)
        {
            LCIDAttrSample smpl = new LCIDAttrSample();
            smpl.CheckCurrentLCID();
        }
    }

using namespace System;
using namespace System::Runtime::InteropServices;
using namespace System::Reflection;

#define LCID_INSTALLED 1
#define LCID_SUPPORTED 2

ref class LCIDAttrSample
{
public:

   // Position of the LCID argument

   [DllImport("KERNEL32.DLL",EntryPoint="IsValidLocale",SetLastError=true,CharSet=CharSet::Auto)]
   [LCIDConversionAttribute(0)]
   static bool IsValidLocale( int dwFlags ); // options

   void CheckCurrentLCID()
   {
      MethodInfo^ mthIfo = this->GetType()->GetMethod( "IsValidLocale" );
      Attribute^ attr = Attribute::GetCustomAttribute( mthIfo, LCIDConversionAttribute::typeid );
      if ( attr != nullptr )
      {
         LCIDConversionAttribute^ lcidAttr = dynamic_cast<LCIDConversionAttribute^>(attr);
         Console::WriteLine( "Position of the LCID argument in the unmanaged signature: {0}", lcidAttr->Value );
      }

      bool res = IsValidLocale( LCID_INSTALLED );
      Console::WriteLine( "Result LCID_INSTALLED {0}", res );
      res = IsValidLocale( LCID_SUPPORTED );
      Console::WriteLine( "Result LCID_SUPPORTED {0}", res );
   }
};

int main()
{
   LCIDAttrSample^ smpl = gcnew LCIDAttrSample;
   smpl->CheckCurrentLCID();
}