VB.NET 获取AutoCAD图层交点平面坐标

可以使用AutoCAD的API来实现在VB.NET中获取两个图层相交点的平面坐标，并输出。下面是一个示例代码：

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

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

        Using trans As Transaction = db.TransactionManager.StartTransaction()
            ' 打开当前空间的块表
            Dim bt As BlockTable = CType(trans.GetObject(db.BlockTableId, OpenMode.ForRead), BlockTable)

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

            ' 获取图层的Id
            Dim sjxLayerId As ObjectId = GetLayerId('sjx') ' 替换为sjx图层的名字
            Dim dmxLayerId As ObjectId = GetLayerId('dmx') ' 替换为dmx图层的名字

            ' 遍历模型空间中的所有实体
            For Each objId As ObjectId In ms
                Dim entity As Entity = CType(trans.GetObject(objId, OpenMode.ForRead), Entity)

                ' 判断实体是否在sjx图层或dmx图层中
                If entity.LayerId.Equals(sjxLayerId) OrElse entity.LayerId.Equals(dmxLayerId) Then
                    ' 获取与sjx图层和dmx图层相交的实体
                    Dim intersectionPoints As Point3dCollection = New Point3dCollection()
                    entity.IntersectWith(entity, Intersect.OnBothOperands, intersectionPoints, IntPtr.Zero, IntPtr.Zero)

                    ' 输出相交点坐标
                    For Each point As Point3d In intersectionPoints
                        doc.Editor.WriteMessage('Intersection Point: ' & point.ToString())
                    Next
                End If
            Next
            trans.Commit()
        End Using
    End Sub

    ' 根据图层名字获取图层的Id
    Private Shared Function GetLayerId(layerName As String) As ObjectId
        Dim doc As Document = Application.DocumentManager.MdiActiveDocument
        Dim db As Database = doc.Database

        Using trans As Transaction = db.TransactionManager.StartTransaction()
            Dim lt As LayerTable = CType(trans.GetObject(db.LayerTableId, OpenMode.ForRead), LayerTable)

            If lt.Has(layerName) Then
                Dim layerId As ObjectId = lt(layerName)
                Return layerId
            End If
        End Using

        Return ObjectId.Null
    End Function
End Class

在上面的代码中，GetIntersectionPoints方法用于获取两个图层相交点的平面坐标并输出。GetLayerId方法用于根据图层名字获取图层的Id。

你需要将代码中的'sjx'和'dmx'替换为你实际使用的sjx图层和dmx图层的名字。

请注意，为了在VB.NET中使用AutoCAD的API，你需要将Autodesk.AutoCAD.ApplicationServices、Autodesk.AutoCAD.DatabaseServices、Autodesk.AutoCAD.EditorInput和Autodesk.AutoCAD.Geometry这四个引用添加到你的项目中。