C#画图可保存cad文件，并加载cad文件

using System;
using System.Collections.Generic;
using System.Text;
using System.Drawing;

namespace CAD
{
    [Serializable]
    public abstract class baseShape
    {        
        private bool isSelected = false;

        private Point p1;
        private Point p2;

        public void setSelected（）
        {
            this.isSelected = true;
        }
        public void setUnSelected（）
        {
            this.isSelected = false;
        }
        public Point getP1（）
        {
            return p1;
        }
        public void setP1（Point p1）
        {
            this.p1 = p1;
        }
        public Point getP2（）
        {
            return p2;
        }
        public void setP2（Point p2）
        {
            this.p2 = p2;
        }

 属性            大小     日期    时间   名称
----------- ---------  ---------- -----  ----
     目录           0  2019-09-30 12:56  CAD\
     目录           0  2019-09-30 12:56  CAD\CAD\
     文件        2756  2008-08-27 15:08  CAD\CAD\baseShape.cs
     文件        4147  2008-08-28 16:13  CAD\CAD\baseTool.cs
     文件        3425  2008-08-27 16:06  CAD\CAD\CAD.csproj
     文件        7751  2008-08-28 16:27  CAD\CAD\CADframe.Designer.cs
     文件        7910  2008-08-28 16:50  CAD\CAD\CADframe.cs
     文件        6221  2008-08-28 16:27  CAD\CAD\CADframe.resx
     文件        3195  2008-08-27 16:36  CAD\CAD\HandTool.cs
     文件        2639  2008-08-28 16:55  CAD\CAD\LineShape.cs
     文件        1051  2008-08-28 15:29  CAD\CAD\LineTool.cs
     文件         465  2008-08-27 14:43  CAD\CAD\Program.cs
     目录           0  2019-09-30 12:56  CAD\CAD\Properties\
     文件        1162  2008-08-27 14:24  CAD\CAD\Properties\AssemblyInfo.cs
     文件        2862  2008-08-27 14:24  CAD\CAD\Properties\Resources.Designer.cs
     文件        5612  2008-08-27 14:24  CAD\CAD\Properties\Resources.resx
     文件        1088  2008-08-27 14:24  CAD\CAD\Properties\Settings.Designer.cs
     文件         249  2008-08-27 14:24  CAD\CAD\Properties\Settings.settings
     目录           0  2019-09-30 12:56  CAD\CAD\bin\
     目录           0  2019-09-30 12:56  CAD\CAD\bin\Debug\
     文件       28672  2008-08-28 16:55  CAD\CAD\bin\Debug\CAD.exe
     文件       65024  2008-08-28 16:55  CAD\CAD\bin\Debug\CAD.pdb
     文件        5632  2005-12-08 14:51  CAD\CAD\bin\Debug\CAD.vshost.exe
     目录           0  2019-09-30 12:56  CAD\CAD\obj\
     文件         419  2008-08-28 16:56  CAD\CAD\obj\CAD.csproj.FileListAbsolute.txt
     目录           0  2019-09-30 12:56  CAD\CAD\obj\Debug\
     文件         180  2008-08-28 16:27  CAD\CAD\obj\Debug\CAD.CADframe.resources
     文件         180  2008-08-28 16:07  CAD\CAD\obj\Debug\CAD.Properties.Resources.resources
     文件         845  2008-08-28 16:27  CAD\CAD\obj\Debug\CAD.csproj.GenerateResource.Cache
     文件       28672  2008-08-28 16:55  CAD\CAD\obj\Debug\CAD.exe
     文件       65024  2008-08-28 16:55  CAD\CAD\obj\Debug\CAD.pdb
............此处省略2个文件信息