//先将DXF文件中的Ellipse 解析到elpList 中

 foreach (Ellipse ellipse in elpList)

       {

         //定义一个矩形

         RectangleF rect = new RectangleF();

         //长轴

         float r1 = Convert.ToSingle(ellipse.MajorAxis) * m_fratio;

         //短轴

         float r2 = Convert.ToSingle(ellipse.MinorAxis) * m_fratio;

         //旋转角度

         float rotAg = Convert.ToSingle(ellipse.Rotation);

         //中心点 显示坐标转换

         PointF pf = DisplayCoordinateConversion(ellipse.Center);

         GraphicsContainer state = graphics.BeginContainer();//  建一个新绘图状态

         graphics.TranslateTransform(pf.X, pf.Y);//坐标系移动到椭圆中心

         rect.X = r1 / -2;

         rect.Y = r2 / -2;

         rect.Width = r1;

         rect.Height = r2;

         graphics.RotateTransform(Math.Abs(rotAg - 180f)); //坐标旋转一定角度

         graphics.DrawEllipse(pen1, rect);//绘制椭圆

         graphics.EndContainer(state);//  关闭绘图状态

　　 }

        /// <summary>

        /// 显示坐标转换

        /// 把DXF文件的三维坐标点转换成PictureBox显示的坐标点

        /// </summary>

        /// <param name="vector3">输入的三维坐标点</param>

        /// <returns>返回转换完成的显示坐标点</returns>

        public PointF DisplayCoordinateConversion(Vector3 vector3)

        {

            PointF pf = new PointF

            {

                X = Convert.ToSingle(vector3.X - viewcCenterX) * m_fratio * m11 + m13,

                Y = Convert.ToSingle(vector3.Y - viewcCenterY) * m_fratio * m22 + m23

            };

            return pf;

        }

/// <summary>

/// 显示比例

/// </summary>

static float m_fratio;

/// <summary>

/// 起始角度

/// </summary>

static float starAg;

/// <summary>

/// 范围角度

/// </summary>

static float sweepAg;

/// <summary>

/// X 坐标偏移比例

/// </summary>

static float m11;

/// <summary>

/// Y 坐标偏移比例

/// </summary>

static float m22;

/// <summary>

/// 坐标偏移量 X

/// </summary>

static float m13;

/// <summary>

/// 坐标偏移量 Y

/// </summary>

static float m23;

/// <summary>

/// DXF文件视窗中点X坐标

/// </summary>

static double viewcCenterX;

/// <summary>

/// DXF文件视窗中点Y坐标

/// </summary>

static double viewcCenterY;

/// <summary>

/// DXF文件视窗高度

/// </summary>

static double viewcCenterH;

m11 = 1f;

m22 = -1f;

m13 = 0f;

m23 = 0f;

            //视窗中心坐标

            viewcCenterX = dxf.Viewport.ViewCenter.X;

            viewcCenterY = dxf.Viewport.ViewCenter.Y;

            //视窗高度

            viewcCenterH = dxf.Viewport.ViewHeight;

            //根据视窗高度和显示框高度调整图形显示比例

            m_fratio = (float)(MainPic.Size.Height / viewcCenterH);