private void Manip_ManipulationUpdate(object sender, ManipulationGestureEventArgs e)
{
var postit = sender as Postit;
var matrix = (postit.RenderTransform != null) ? postit.RenderTransform.Value : new Matrix();
Point ct = new Point(postit.RenderSize.Width / 2, postit.RenderSize.Height / 2);
// transform it to take into account transforms from previous manipulations
ct = matrix.Transform(ct);
//this will be a Zoom.
matrix.ScaleAt(e.Delta.ScaleX, e.Delta.ScaleY, ct.X, ct.Y);
// Rotation
matrix.RotateAt(Geometry2DHelper.RadiansToDegree(e.Delta.Rotation), ct.X, ct.Y);
//Translation (pan)
matrix.Translate(e.Delta.TranslationX, e.Delta.TranslationY);
postit.RenderTransform = new MatrixTransform(matrix);
}
void manip_ManipulationUpdate(object sender, ManipulationGestureEventArgs e)
{
e.ApplyDeltaOnRenderTransform();
}