private void ArrangeTree()
{
using (Graphics gr = treePictureBox.CreateGraphics())
{
// Arrange the tree once to see how big it is.
float xmin = 0, ymin = 10;
Root.Arrange(gr, treePictureBox.Font, ref xmin, ref ymin);
// Translate the tree to center it.
float dx = (treePictureBox.ClientSize.Width - xmin) / 2f;
Root.Translate(dx, 0);
}
treePictureBox.Refresh();
}