Android Question animate view

Sub Globals
   'These global variables will be redeclared each time the activity is created.
   'These variables can only be accessed from this module.
   Dim button1 As Button
End Sub

Sub Activity_Create(FirstTime As Boolean)
   Activity.LoadLayout("1")
   If FirstTime Then
     timer1.Initialize("timer1", 16)
   End If
   startTimer = DateTime.Now
   timer1.Enabled = True
End Sub

Sub Timer1_Tick
   Dim t As Float = (DateTime.Now - startTimer) / 5000 '0 to 1
   Dim r As Float = 200dip * t
   Dim ang As Float = 5 * 360 * t
   Dim x = r * SinD(ang), y = r * CosD(ang) As Float
   button1.Left = 45%x + x
   button1.Top = 45%y + y
   If t >= 1 Then timer1.Enabled = False
End Sub