C# 实现读取DXF文件并显示dxf 图像

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.Drawing.Drawing2D;



namespace ex3_txf
{

   
    public partial class Form1 : Form
    {
        public struct DataLineStruct
        {
            public int iLineType;
            public float fX1Pos;
            public float fY1Pos;
            public float fZ1Pos;
            public float fX2Pos;
            public float fY2Pos;
            public float fZ2Pos;
        };

        public struct DataPolyLineStruct
        {
            public int iLineType;
            public int iNum;
            public float fX1Pos;
            public flo