我无法显示txt文件。我假设DisplayShape方法有问题，但不知道如何解决

Question

    public class Program
    {
        private static readonly ILog logger = log4net.LogManager.GetLogger
            (System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);

        public static void Main(string[] args)
        {
            log4net.Config.XmlConfigurator.Configure();

            logger.Debug("Starting the main driver program");

            ShapeManager manager = new ShapeManager("data.txt");
            manager.DisplayShapes();

            logger.Debug("Exiting the main program");
            System.Console.ReadLine();

_______________________________

public class ShapeManager
    {
        private static readonly ILog logger =
            log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);

        private string datafile;
        private List<Shape> shapes;
        private StreamReader sr;

        public ShapeManager()
        {

        }

        public ShapeManager(string datafile)
        {
            logger.Debug("Starting manager");
            this.datafile = datafile;
            shapes = new List<Shape>();
        }


        public void ReadDataFile()
        {
            string line;
            double xcoord;
            double ycoord;
            double radius;
            double height;
            double width;

            sr = new StreamReader(datafile);
            Shape tempshape = null;

            while (!sr.EndOfStream)
            {
                line = sr.ReadLine();
                var elements = line.Split('|');

                xcoord = Convert.ToDouble(elements[1]);
                ycoord = Convert.ToDouble(elements[2]);
                radius = Convert.ToDouble(elements[3]);
                width = Convert.ToDouble(elements[3]);
                height = Convert.ToDouble(elements[4]);

                if (elements[0].ToLower().Equals("c"))
                {
                    tempshape = new Circle(xcoord, ycoord, radius);
                }

                if (elements[0].ToLower().Equals("r"))
                {
                    tempshape = new Rectangle(xcoord, ycoord, width, height);
                }

                shapes.Add(tempshape);
            }
            sr.Close();
            sr.Dispose();
        }

        public void DisplayShapes()
        {
            foreach (Shape temp in shapes)
            {
                temp.Display();
            }
        }

---

这是data.txt文件

c | 1.1 | 2.2 | 3.3 r | 1.1 | 2.2 | 3.3 | 4.4 c | 2.2 | 3.3。| 4.4 r | 2.2 | 3.3 | 4.4。| 5.5

---

我假设我的问题不在主程序本身，而是在shapemanager的displayshape方法下。我似乎不知道。我还没有发布其他3个课程，但我不认为这些课程会导致我遇到问题。