Binaryworld - CreateFileAssociation - Creating a new file association ... [ VB.net -> Windows ]

<System.Runtime.InteropServices.DllImport("shell32.dll")> Shared Sub _
  SHChangeNotify(ByVal wEventId As Integer, ByVal uFlags As Integer, _
  ByVal dwItem1 As Integer, ByVal dwItem2 As Integer)
End Sub

' Create the new file association
'
' Extension is the extension to be registered (eg ".cad"
' ClassName is the name of the associated class (eg "CADDoc")
' Description is the textual description (eg "CAD Document"
' ExeProgram is the app that manages that extension (eg "c:\Cad\MyCad.exe")

Function CreateFileAssociation(ByVal extension As String, _
  ByVal className As String, ByVal description As String, _
  ByVal exeProgram As String) As Boolean
  Const SHCNE_ASSOCCHANGED = &H8000000
  Const SHCNF_IDLIST = 0

  ' ensure that there is a leading dot
  If extension.Substring(0, 1) <> "." Then
    extension = "." & extension
  End If

  Dim key1, key2, key3 As Microsoft.Win32.RegistryKey
  Try
    ' create a value for this key that contains the classname
    key1 = Microsoft.Win32.Registry.ClassesRoot.CreateSubKey(extension)
    key1.SetValue("", className)
    ' create a new key for the Class name
    key2 = Microsoft.Win32.Registry.ClassesRoot.CreateSubKey(className)
    key2.SetValue("", description)
    ' associate the program to open the files with this extension
    key3 = Microsoft.Win32.Registry.ClassesRoot.CreateSubKey(className & _
      "\Shell\Open\Command")
    key3.SetValue("", exeProgram & " ""%1""")
  Catch e As Exception
    Return False
  Finally
    If Not key1 Is Nothing Then key1.Close()
    If Not key2 Is Nothing Then key2.Close()
    If Not key3 Is Nothing Then key3.Close()
  End Try

  ' notify Windows that file associations have changed
  SHChangeNotify(SHCNE_ASSOCCHANGED, SHCNF_IDLIST, 0, 0)
  Return True
End Function