VS 2008 - Converting String To Date

I use following codes to to convert string to date. In messagebox it displays correct date with format but in textbox it displays only #12:00:00 AM #. How to send date to textbox1 from variable mydate.

Dim mydate As Date
Dim dateString = "31/12/2009"
Dim formats As String() = {"dd/MM/yyyy", "dd/MM/yyyy"}
Dim dateObject As DateTime = DateTime.ParseExact(dateString, formats, System.Globalization.CultureInfo.InvariantCulture, Globalization.DateTimeStyles.NoCurrentDateDefault)
MessageBox.Show(dateObject.ToString("dd/MM/yyyy"))
Me.TextBox1.Text = mydate