public Trackball ()
		{
			chart 					        = new SFChart ();
			SFNumericalAxis primaryAxis     = new SFNumericalAxis ();
			chart.PrimaryAxis 				= primaryAxis;
			SFNumericalAxis secondaryAxis 	= new SFNumericalAxis ();
			chart.SecondaryAxis 			= secondaryAxis;
			ChartTrackballDataSource dataModel 	= new ChartTrackballDataSource ();
			chart.DataSource 				= dataModel as SFChartDataSource;

			label 					= new UILabel ();
			label.Text 				= "Press and hold to enable trackball";
			label.Font				= UIFont.FromName("Helvetica", 12f);
			label.TextAlignment 	= UITextAlignment.Center;
			label.LineBreakMode 	= UILineBreakMode.WordWrap;
			label.Lines 			= 2; 
			label.BackgroundColor   = UIColor.Black.ColorWithAlpha (0.7f);
			label.TextColor 		= UIColor.White;


			chart.AddChartBehavior (new SFChartTrackballBehavior());
			this.AddSubview (chart);
			this.AddSubview (label);
			this.control = this;
		}
        public Trackball()
        {
            chart = new SFChart();
            SFNumericalAxis primaryAxis = new SFNumericalAxis();

            chart.PrimaryAxis = primaryAxis;
            SFNumericalAxis secondaryAxis = new SFNumericalAxis();

            chart.SecondaryAxis = secondaryAxis;
            ChartTrackballDataSource dataModel = new ChartTrackballDataSource();

            chart.DataSource = dataModel as SFChartDataSource;

            label                 = new UILabel();
            label.Text            = "Press and hold to enable trackball";
            label.Font            = UIFont.FromName("Helvetica", 12f);
            label.TextAlignment   = UITextAlignment.Center;
            label.LineBreakMode   = UILineBreakMode.WordWrap;
            label.Lines           = 2;
            label.BackgroundColor = UIColor.Black.ColorWithAlpha(0.7f);
            label.TextColor       = UIColor.White;


            chart.AddChartBehavior(new SFChartTrackballBehavior());
            this.AddSubview(chart);
            this.AddSubview(label);
            this.control = this;
        }