Classe d'extraction de ressource Bitmap (P/Invoke)

'########################################################
' Credits 3DotDev from http://3dotdevcoder.blogspot.fr/
'########################################################
Imports System.Runtime.InteropServices

Public Class Cls_ExtractBmp

                Private bmp As Bitmap
                Private hRes As IntPtr = IntPtr.Zero
                Private hLib As IntPtr = IntPtr.Zero
                Private m_filename As String = String.Empty
                Private m_ResName As Integer = 0

                Private Const LOAD_LIBRARY_AS_IMAGE_RESOURCE As Integer = 32
                Private Const LOAD_LIBRARY_AS_DATAFILE As Integer = 2

                Private Declare Function LoadLibraryEx Lib "kernel32" (ByVal lpLibFileName As String, ByVal hModule As IntPtr, ByVal dwFlags As Integer) As IntPtr

                Private Declare Function FreeLibrary Lib "kernel32" (ByVal hLibModule As Long) As IntPtr

                Private Declare Function LoadBitmap Lib "user32" Alias "LoadBitmapA" (ByVal hInstance As IntPtr, ByVal lpBitmapName As String) As IntPtr

                Public Sub New(ByVal Filename As String, ByVal ResName As Integer)
                        m_filename = Filename
                        m_ResName = ResName
                End Sub

                Public Property Filename() As String
                        Get
                                Return m_filename
                        End Get
                        Set(ByVal value As String)
                                m_filename = value
                        End Set
                End Property

                Public Property ResName() As String
                        Get
                                Return m_ResName
                        End Get
                        Set(ByVal value As String)
                                m_ResName = value
                        End Set
                End Property

                Private ReadOnly Property Handle() As IntPtr
                        Get
                                Return hLib
                        End Get
                End Property

                Public Function GetImg() As Bitmap
                        ClearUp()
                        hLib = LoadLibraryEx(m_filename, IntPtr.Zero, LOAD_LIBRARY_AS_DATAFILE + LOAD_LIBRARY_AS_IMAGE_RESOURCE)
                        If hLib <> Nothing Then
                                hRes = LoadBitmap(hLib, ResName)
                                If hRes <> 0 Then
                                        bmp = Bitmap.FromHbitmap(hRes)
                                        FreeLibrary(hLib)
                                End If
                        End If
                        Return bmp
                End Function

                Private Sub ClearUp()
                        If Not hLib.Equals(IntPtr.Zero) Then
                                FreeLibrary(hLib)
                                hLib = IntPtr.Zero
                        End If
                End Sub

        End Class

'##############################
' Comment utiliser cette classe
'##############################

        'Instanciation d'un objet de type PictureBox
        Dim Pbx as new PictureBox

        'Si PictureBox déjà chargée alors suppression de l'image
        If Not (Pbx.Image Is Nothing) Then
            Pbx.Image.Dispose()
            Pbx.Image = Nothing
        End If

        'Affichage de la ressource Bitmap 6801 dans la PictureBox en utilisant la classe "Cls_ExtractBmp"
        If File.Exists(My.Application.GetEnvironmentVariable("SYSTEMDRIVE") & "Windows\explorer.exe") Then
            Dim ext1 As New Cls_ExtractBmp(My.Application.GetEnvironmentVariable("SYSTEMDRIVE") & "Windows\explorer.exe", 6801)
            Pbx.Image = ext1.GetImg
        End If