另一个“对象不包含X的定义”

Question

我看到了很多关于这个问题的主题：

“对象不包含X的定义，并且没有扩展方法X接受Object类型的第一个参数”

但他们都没有解决我的问题。

情况： 我想保存3个系列的DataPoints。因此我制作了一个包含该系列的列表：

List<OxyPlot.Series.DataPointSeries> filesToBeStored;
    public OxyPlot.Series.DataPointSeries saveAnalyseBSITotal;
    public OxyPlot.Series.DataPointSeries saveAnalyseSBSI;
    public OxyPlot.Series.DataPointSeries saveAnalyseTBSI;

在Form.cs中，我调用SaveFile（...）：

        for (int i = 0; i < plotSBSIBandsA.Model.Series.Count; i++)
        {
            OxyPlot.Series.DataPointSeries sA = (plotSBSIBandsA.Model.Series[i] as OxyPlot.Series.DataPointSeries);
            OxyPlot.Series.DataPointSeries sB = (plotSBSIBandsB.Model.Series[i] as OxyPlot.Series.DataPointSeries);
            sB.Points.Clear();

            for (int j = 0; j < sA.Points.Count; j++)
            {
                sB.Points.Add(new OxyPlot.DataPoint(sA.Points[j].X, sA.Points[j].Y));
            }
        }
        if(saveButtonClicked)
            {this.SaveFile(sB)}

完整的Save-Class是：

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;

 namespace BSIAnalyzer
 {
     class SaveFile
     {

    List<OxyPlot.Series.DataPointSeries> filesToBeStored;
    public OxyPlot.Series.DataPointSeries saveAnalyseBSITotal;
    public OxyPlot.Series.DataPointSeries saveAnalyseSBSI;
    public OxyPlot.Series.DataPointSeries saveAnalyseTBSI;

    public SaveFile(OxyPlot.Series.DataPointSeries sA)
    {
        for (int i = 0; i < sA.Points.Count; i++)
        {
            saveAnalyseBSITotal.Points.Add(new OxyPlot.DataPoint(sA.Points[i].X, sA.Points[i].Y));
        }
    }

    public SaveFile(List<OxyPlot.Series.DataPointSeries> series)
         {
             filesToBeStored.Insert(0, saveAnalyseBSITotal);
             filesToBeStored.Insert(1, saveAnalyseSBSI);
             filesToBeStored.Insert(2, saveAnalyseTBSI);

             for (int k = 0; k < series.Count; k++)
             {
                 filesToBeStored[k].Points.Add(new OxyPlot.DataPoint(series[k].Points.X, series[k].Points.Y));
             }
         }
     }
 }

在te“k”的forloop中我得到了错误。