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