adding series to chart control in runtime asp.net (because of postback problem)

Question

after the postback the chart control's values is changing its design time values. even when i write page load actions in (!isPostBack) scope , the values resets. so i defined a "my series" static ArrayList and in runtime i added each series of chart to that ArrayList. And in the page load event i added each element of ArrayList to Chart with Chart1.Series.Add(myseries[i] as Series) method. But it failed. "object reference not set to an instance of an object" error occured. Here is my code. Where am i wrong?

public partial class _Default : System.Web.UI.Page
{
   static ArrayList my_series = new ArrayList();

   void Fill_Chart();
   {
      ....
      foreach (Series item in Chart1.Series)
      {
          my_series.Add(item);
      }
   }

   protected void Page_Load(object sender, EvetnArgs e)
   {
      ...
      Chart1.Series.Clear();
      for (int i=0;i < my_series.Count;i++)
      {
         Chart1.Series.Add(my_series[i] as Series)
      }
   }

i checked this steps with debug. the error didnt occur after passing the line with F10. But when i passed last } symbol in page load event this error occurs.Any idea?

Answer 1

Why is my_series static? You can use like this:

public partial class _Default : System.Web.UI.Page
{
    private ArrayList mySeries;
    public ArrayList MySeries
    {
        get
        {
            if (mySeries == default(ArrayList))
                mySeries = new ArrayList();
            return mySeries;
        }
    }

   void Fill_Chart()
   {
      foreach (Series item in Chart1.Series)
      {
          MySeries.Add(item);
      }
   }

   protected void Page_Load(object sender, EvetnArgs e)
   {
      ...
      Chart1.Series.Clear();
      Fill_Chart();
      for (int i=0;i < MySeries.Count;i++)
      {
         Chart1.Series.Add(MySeries[i] as Series)
      }
   }
}