Spanish Formato Fecha en EditText

EditText.InputType=EditText.INPUT_TYPE_DECIMAL_NUMBERS

' En el diseñador definir los EditText para las fechas con InputType = Numbers
' Y casi sería más interesante definir el mismo evento para todos, ya que luego gracias al Sender ya sabría realmente de que Editbox se trata en cada momento.
' En el ejemplo lo pongo por separado para que se vea que el mismo MascaraFecha me sirve para tantos EditText de tipo fecha como sea necesario.

Sub EditFCaducidad_TextChanged (Old As String, New As String)
    Dim Edit = Sender As EditText    
    MascaraFecha(Edit, Old, New)
End Sub

Sub EditFAlbaran_TextChanged (Old As String, New As String)
    Dim Edit = Sender As EditText    
    MascaraFecha(Edit, Old, New)
End Sub

Sub MascaraFecha(Edit As EditText, Old As String, New As String)
    Log("Old: " & Old & " - New: " & New)
    If (New.Length = 3) And (New.CharAt(2) <> "/") Then Edit.Text = Edit.text.SubString2(0,2) & "/" & New.CharAt(2)
    If (New.Length = 6) And (New.CharAt(5) <> "/") Then Edit.Text = Edit.text.SubString2(0,5) & "/" & New.CharAt(5)
    If (New.Length = 8) And (New.Length > Old.Length) Then 
        DateTime.DateFormat="dd/MM/yy"
        Dim DateAux = DateTime.DateParse(Edit.text) As Long 
        DateTime.DateFormat="dd/MM/yyyy"
        Edit.Text = DateTime.Date(DateAux)
    End If
    Edit.SelectionStart = Edit.Text.Length
End Sub

Sub EditFCaducidad_TextChanged (Old As String, New As String)
    Dim Edit = Sender As EditText   
    MascaraFecha(Edit, Old, New)
End Sub

Sub EditFAlbaran_TextChanged (Old As String, New As String)
    Dim Edit = Sender As EditText   
    MascaraFecha(Edit, Old, New)
End Sub

Sub MascaraFecha(Edit As EditText, Old As String, New As String)
    Log("Old: " & Old & " - New: " & New)
    If New.Length > Old.Length And "01234567890/".IndexOf(New.CharAt(New.Length-1)) = -1 Then Edit.Text = Old
    If (New.Length = 3) And (New.CharAt(2) <> "/") Then Edit.Text = Edit.text.SubString2(0,2) & "/" & New.CharAt(2)
    If (New.Length = 6) And (New.CharAt(5) <> "/") Then Edit.Text = Edit.text.SubString2(0,5) & "/" & New.CharAt(5)
    If (New.Length = 8) And (New.Length > Old.Length) Then
        If IsValidDate(New) Then
                DateTime.DateFormat="dd/MM/yy"
                Dim DateAux = DateTime.DateParse(New) As Long
                DateTime.DateFormat="dd/MM/yyyy"
                Edit.Text = DateTime.Date(DateAux)
            Else
                Msgbox("Fecha incorrecta", "Aviso")
        End If
    End If
    Edit.SelectionStart = Edit.Text.Length
    ime1.SetCustomFilter(Edit, Edit.INPUT_TYPE_NUMBERS, "0123456789/")
End Sub

Sub IsValidDate(Date As String) As Boolean
    Try
        DateTime.DateParse(Date)
        Return True
    Catch
        Return False
    End Try
End Sub