Set the line displayed in the chart pie chart, and display the percentage

 chart1.Series["serYearPlay"].Points.DataBindXY(xvar, yvar);
            chart1.TextAntiAliasingQuality = TextAntiAliasingQuality.High;
            this.chart1.Series["serYearPlay"].Label = "#VALX (#PERCENT)";// "#PERCENT";
            this.chart1.Series["serYearPlay"].LegendText = "#VALX";
            chart1.Series["serYearPlay"]["PieLabelStyle"] = "OutSide";