C# 要重置图表的xml数据？根据新数据

所以每次都是这样

OpenFileDialog xmlOpenFileDialog = new OpenFileDialog();
xmlOpenFileDialog.Filter = @"XML|*.xml";
xmlOpenFileDialog.FilterIndex = 1;
//Start
//Implement a way for user to have last opened file shown if program is closed by accident?
//xmlOpenFileDialog.InitialDirectory = System.Environment.GetFolderPath(Environment.SpecialFolder.DesktopDirectory);
//End
xmlOpenFileDialog.Multiselect = false;
DialogResult userClickedOk = xmlOpenFileDialog.ShowDialog();

if (userClickedOk == DialogResult.OK)
{
    lastKnownFileName = xmlOpenFileDialog.FileName;
    System.IO.Stream filestream = xmlOpenFileDialog.OpenFile();

    using (System.IO.StreamReader reader = new StreamReader(filestream))
    {
        UpChart_Chart.Serializer.IsResetWhenLoading = false;
        UpChart_Chart.Serializer.Content = SerializationContents.Data;

        UpChart_Chart.Serializer.SerializableContent += ",DataPoint.AxisLabel,DataPoint.Label,Series.AxisLabels,Series.Name,Series.ChartType,ChartChartArea.Name";

        UpChart_Chart.Serializer.Load(reader);
    }

那么，当新的输入发生时，图表中的数据会重置吗？ 我们如何确保我们拥有的数据正确地放在正确的区域