#807 – Setting the Position of Child Elements in a Canvas from Code

Recall that you position child elements in a Canvas panel by setting at most two out of four of the following attached properties: Left, Right, Top, Bottom.  In all cases, you set a property to a value expressed in WPF (device-independent) units, equivalent to 1/96 inch.

You set any of these four values from code using one of the following static methods of the Canvas property:

• Canvas.SetLeft
  
• Canvas.SetRight
• Canvas.SetTop
• Canvas.SetBottom

        // Whenever we move mouse over label, put it somewhere else
        private void Label_MouseMove(object sender, MouseEventArgs e)
        {
            Label lbl = sender as Label;
            Canvas canv = lbl.Parent as Canvas;

            Random rand = new Random();

            // Set position to random location
            Canvas.SetLeft(sender as UIElement,
                           rand.Next((int)(canv.ActualWidth - lbl.ActualWidth)));
            Canvas.SetTop(sender as UIElement,
                          rand.Next((int)(canv.ActualHeight - lbl.ActualHeight)));
        }