vbnet 在autocad当中提取所有zhix图层和dmx图层相交点坐标以此点为中心点提取左侧dmx图层多段线上所有变化点坐标数据并计算后一个点与前一个点坐标的距离和高差值并输出到文本

以下是一个在AutoCAD中使用VB.NET编写的示例代码，用于提取zhix图层和dmx图层相交点坐标，并提取左侧dmx图层多段线上所有变化点的坐标数据，并计算距离和高差值，然后将结果输出到文本文件中。

Imports Autodesk.AutoCAD.ApplicationServices
Imports Autodesk.AutoCAD.DatabaseServices
Imports Autodesk.AutoCAD.EditorInput
Imports Autodesk.AutoCAD.Geometry
Imports System.IO

Public Class ExtractData
    Public Sub ExtractIntersectionData()
        ' 获取当前文档和数据库
        Dim doc As Document = Application.DocumentManager.MdiActiveDocument
        Dim db As Database = doc.Database

        ' 开始事务
        Using trans As Transaction = db.TransactionManager.StartTransaction()
            ' 打开块表
            Dim bt As BlockTable = trans.GetObject(db.BlockTableId, OpenMode.ForRead)

            ' 获取模型空间块表记录
            Dim ms As BlockTableRecord = trans.GetObject(bt(BlockTableRecord.ModelSpace), OpenMode.ForRead)

            ' 获取图层表
            Dim lt As LayerTable = trans.GetObject(db.LayerTableId, OpenMode.ForRead)

            ' 获取zhix图层和dmx图层的图层ID
            Dim zhixLayerId As ObjectId = GetLayerId(lt, "zhix")
            Dim dmxLayerId As ObjectId = GetLayerId(lt, "dmx")

            ' 创建文件流，用于写入结果
            Dim outputFile As New FileStream("output.txt", FileMode.Create)
            Dim writer As New StreamWriter(outputFile)

            ' 遍历模型空间中的实体
            For Each objId As ObjectId In ms
                Dim ent As Entity = trans.GetObject(objId, OpenMode.ForRead)

                ' 如果实体在zhix图层或dmx图层上
                If ent.LayerId.Equals(zhixLayerId) OrElse ent.LayerId.Equals(dmxLayerId) Then
                    ' 获取实体的交点
                    Dim intPoints As New Point3dCollection()
                    If ent.GetIntersectionPoints(ent, Intersect.OnBothOperands, intPoints, IntPtr.Zero) > 0 Then
                        ' 遍历交点
                        For Each pt As Point3d In intPoints
                            ' 以交点为中心点，提取左侧dmx图层多段线上所有变化点的坐标数据
                            If ent.LayerId.Equals(dmxLayerId) AndAlso TypeOf ent Is Polyline Then
                                Dim polyline As Polyline = CType(ent, Polyline)

                                ' 获取多段线上的点
                                Dim points As New List(Of Point3d)()
                                For i As Integer = 0 To polyline.NumberOfVertices - 1
                                    points.Add(polyline.GetPoint3dAt(i))
                                Next

                                ' 计算距离和高差值
                                For i As Integer = 1 To points.Count - 1
                                    Dim distance As Double = points(i).DistanceTo(points(i - 1))
                                    Dim elevationDifference As Double = points(i).Z - points(i - 1).Z

                                    ' 写入结果到文本文件
                                    writer.WriteLine("Distance: " & distance & ", Elevation Difference: " & elevationDifference)
                                Next
                            End If
                        Next
                    End If
                End If
            Next

            ' 关闭文件流
            writer.Close()
        End Using
    End Sub

    Private Function GetLayerId(layerTable As LayerTable, layerName As String) As ObjectId
        ' 遍历图层表
        For Each objectId As ObjectId In layerTable
            Dim layer As LayerTableRecord = objectId.GetObject(OpenMode.ForRead)

            ' 如果找到图层名称匹配的图层，返回图层ID
            If layer.Name.Equals(layerName, StringComparison.OrdinalIgnoreCase) Then
                Return objectId
            End If
        Next

        ' 如果未找到匹配的图层，返回无效的ObjectId
        Return ObjectId.Null
    End Function
End Class

要使用该代码，可以在AutoCAD的VB.NET环境中创建一个新的模块，然后将上述代码复制到该模块中。然后，您可以调用ExtractIntersectionData方法，以在AutoCAD中提取所需的数据并将其写入文本文件中。

请注意，此代码假设zhix图层和dmx图层已在AutoCAD中定义，并且模型空间中存在使用这些图层的实体。还要注意，此代码仅处理dmx图层上的多段线实体，并计算多段线上的点之间的距离和高差值。如果需要处理其他类型的实体或执行其他操作，请根据需要进行修改