Painting the Canvas with Silverlight 2.0

Now that Silverlight 2.0 BETA 1 is out, developers are discovering some unique and compelling applications. Here is a short example of how to paint a Silverlight Canvas with randomly colored and sized rectangles.

System.Windows.Threading.DispatcherTimer dt = new System.Windows.Threading.DispatcherTimer();

The timer has a callback and a start method:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;

namespace SLPainting
{
    public partial class Page : UserControl
    {
        System.Windows.Threading.DispatcherTimer dt = new System.Windows.Threading.DispatcherTimer();
      
        public Page()
        {
            InitializeComponent();
            dt.Interval = new TimeSpan(0, 0, 0, 0, 10); // 10 Milliseconds  
            dt.Tick += new EventHandler(dt_Tick);
            dt.Start();
        }



        void dt_Tick(object sender, EventArgs e)
        {
            Rectangle rect;
            Random rnd = new Random((int)System.DateTime.Now.Ticks);
            int r = rnd.Next(0, 255);
            int g = rnd.Next(0, 255);
            int b = rnd.Next(0, 255);
           // create rectangle with width, height, color and alpha channel opacity
            rect = new Rectangle() { Height = r * 100 % 600, Width = g * 100 % 800, 
                Fill = new SolidColorBrush { Color = Color.FromArgb((byte)r, (byte)r, (byte)g, (byte)b) } };
            Random rnd2 = new Random((int)System.DateTime.Now.Ticks);
            // set the location of the rect
            int left = rnd2.Next(0, 800);
            int top = rnd2.Next(0, 600);
            rect.SetValue(Canvas.LeftProperty, left);
            rect.SetValue(Canvas.TopProperty, top);  
             this.LayoutRoot.Children.Add(rect);
        }

         
    }
}