请写出这个代码

以下是一个基于DXFLib和System.Drawing的示例代码，它可以读取DXF文件并绘制其中的线条：

Imports DXFLib
Imports System.Drawing
Imports System.Drawing.Drawing2D

Public Class Form1
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim dxf As New DXFDocument
        dxf.Load("C:\test.dxf") '替换为您的DXF文件路径

        Dim g As Graphics = Me.CreateGraphics()

        For Each entity As EntityObject In dxf.Entities
            If TypeOf entity Is LineObject Then
                Dim line As LineObject = CType(entity, LineObject)
                Dim startPoint As New PointF(line.Start.X, line.Start.Y)
                Dim endPoint As New PointF(line.End.X, line.End.Y)
                g.DrawLine(Pens.Black, startPoint, endPoint)
            End If
        Next

        g.Dispose()
        dxf = Nothing
    End Sub
End Class

在此示例中，我们使用DXFDocument类从文件中加载DXF文档。然后，我们遍历DXF文件中的每个实体对象，并检查它是否为线条对象。如果是，我们提取其起点和终点坐标，并使用Graphics.DrawLine方法绘制一条线段。请注意，这只是一个示例代码，您需要根据实际需求进行修改和优化。