裁剪块和外部参照 （.NET）

可通过修剪外部参照来定义外部参照的显示和打印区域。裁剪边界必须是 2D 多边形或矩形，其顶点被约束为位于外部参照的边界内。同一外部参照的多个实例可以具有不同的边界。

对象用于定义外部参照的修剪边界的属性。使用对象的属性显示或隐藏剪切边界。SpatialFilterSpatialFilterDefinitionEnabledSpatialFilterDefinition

Imports Autodesk.AutoCAD.Runtime
Imports Autodesk.AutoCAD.ApplicationServices
Imports Autodesk.AutoCAD.DatabaseServices
Imports Autodesk.AutoCAD.Geometry

<CommandMethod("ClippingExternalReference")> _
Public Sub ClippingExternalReference()
    ' Get the current database and start a transaction
    Dim acCurDb As Autodesk.AutoCAD.DatabaseServices.Database
    acCurDb = Application.DocumentManager.MdiActiveDocument.Database

    Using acTrans As Transaction = acCurDb.TransactionManager.StartTransaction()
        ' Create a reference to a DWG file
        Dim PathName As String = "C:\AutoCAD\Sample\Sheet Sets\Architectural\Res\Exterior Elevations.dwg"
        Dim acXrefId As ObjectId = acCurDb.AttachXref(PathName, "Exterior Elevations")

        ' If a valid reference is created then continue
        If Not acXrefId.IsNull Then
            ' Attach the DWG reference to the current space
            Dim insPt As New Point3d(1, 1, 0)
            Using acBlkRef As New BlockReference(insPt, acXrefId)

                Dim acBlkTblRec As BlockTableRecord
                acBlkTblRec = acTrans.GetObject(acCurDb.CurrentSpaceId, OpenMode.ForWrite)

                acBlkTblRec.AppendEntity(acBlkRef)
                acTrans.AddNewlyCreatedDBObject(acBlkRef, True)

                MsgBox("The external reference is attached.")

                Dim mat As Matrix3d = acBlkRef.BlockTransform
                mat.Inverse()

                Dim ptCol As New Point2dCollection

                ' Define the first corner of the clipping boundary
                Dim pt3d As New Point3d(-330, 400, 0)
                pt3d.TransformBy(mat)
                ptCol.Add(New Point2d(pt3d.X, pt3d.Y))

                ' Define the second corner of the clipping boundary
                pt3d = New Point3d(1320, 1120, 0)
                pt3d.TransformBy(mat)
                ptCol.Add(New Point2d(pt3d.X, pt3d.Y))

                ' Define the normal and elevation for the clipping boundary 
                Dim normal As Vector3d
                Dim elev As Double = 0

                If acCurDb.TileMode = True Then
                    normal = acCurDb.Ucsxdir.CrossProduct(acCurDb.Ucsydir)
                    elev = acCurDb.Elevation
                Else
                    normal = acCurDb.Pucsxdir.CrossProduct(acCurDb.Pucsydir)
                    elev = acCurDb.Pelevation
                End If

                ' Set the clipping boundary and enable it
                Using filter As New Filters.SpatialFilter
                    Dim filterDef As New Filters.SpatialFilterDefinition(ptCol, normal, elev, 0, 0, True)
                    filter.Definition = filterDef

                    ' Define the name of the extension dictionary and entry name
                    Dim dictName As String = "ACAD_FILTER"
                    Dim spName As String = "SPATIAL"

                    ' Check to see if the Extension Dictionary exists, if not create it
                    If acBlkRef.ExtensionDictionary.IsNull Then
                        acBlkRef.CreateExtensionDictionary()
                    End If

                    ' Open the Extension Dictionary for write
                    Dim extDict As DBDictionary = acTrans.GetObject(acBlkRef.ExtensionDictionary, OpenMode.ForWrite)

                    ' Check to see if the dictionary for clipped boundaries exists, 
                    ' and add the spatial filter to the dictionary
                    If extDict.Contains(dictName) Then
                        Dim filterDict As DBDictionary = acTrans.GetObject(extDict.GetAt(dictName), OpenMode.ForWrite)

                        If (filterDict.Contains(spName)) Then filterDict.Remove(spName)

                        filterDict.SetAt(spName, filter)
                    Else
                        Using filterDict As New DBDictionary
                            extDict.SetAt(dictName, filterDict)

                            acTrans.AddNewlyCreatedDBObject(filterDict, True)
                            filterDict.SetAt(spName, filter)
                        End Using
                    End If

                    ' Append the spatial filter to the drawing
                    acTrans.AddNewlyCreatedDBObject(filter, True)
                End Using
            End Using

            MsgBox("The external reference is clipped.")
        End If

        ' Save the new objects to the database
        acTrans.Commit()

        ' Dispose of the transaction
    End Using
End Sub

using Autodesk.AutoCAD.Runtime;
using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.Geometry;

[CommandMethod("ClippingExternalReference")]
public void ClippingExternalReference()
{
    // Get the current database and start a transaction
    Database acCurDb;
    acCurDb = Application.DocumentManager.MdiActiveDocument.Database;

    using (Transaction acTrans = acCurDb.TransactionManager.StartTransaction())
    {
        // Create a reference to a DWG file
        string PathName = "C:\\AutoCAD\\Sample\\Sheet Sets\\Architectural\\Res\\Exterior Elevations.dwg";
        ObjectId acXrefId = acCurDb.AttachXref(PathName, "Exterior Elevations");

        // If a valid reference is created then continue
        if (!acXrefId.IsNull)
        {
            // Attach the DWG reference to the current space
            Point3d insPt = new Point3d(1, 1, 0);
            using (BlockReference acBlkRef = new BlockReference(insPt, acXrefId))
            {
                BlockTableRecord acBlkTblRec;
                acBlkTblRec = acTrans.GetObject(acCurDb.CurrentSpaceId, OpenMode.ForWrite) as BlockTableRecord;

                acBlkTblRec.AppendEntity(acBlkRef);
                acTrans.AddNewlyCreatedDBObject(acBlkRef, true);

                Application.ShowAlertDialog("The external reference is attached.");

                Matrix3d mat = acBlkRef.BlockTransform;
                mat.Inverse();

                Point2dCollection ptCol = new Point2dCollection();

                // Define the first corner of the clipping boundary
                Point3d pt3d = new Point3d(-330, 400, 0);
                pt3d.TransformBy(mat);
                ptCol.Add(new Point2d(pt3d.X, pt3d.Y));

                // Define the second corner of the clipping boundary
                pt3d = new Point3d(1320, 1120, 0);
                pt3d.TransformBy(mat);
                ptCol.Add(new Point2d(pt3d.X, pt3d.Y));

                // Define the normal and elevation for the clipping boundary 
                Vector3d normal;
                double elev = 0;

                if (acCurDb.TileMode == true)
                {
                    normal = acCurDb.Ucsxdir.CrossProduct(acCurDb.Ucsydir);
                    elev = acCurDb.Elevation;
                }
                else
                {
                    normal = acCurDb.Pucsxdir.CrossProduct(acCurDb.Pucsydir);
                    elev = acCurDb.Pelevation;
                }

                // Set the clipping boundary and enable it
                using (Autodesk.AutoCAD.DatabaseServices.Filters.SpatialFilter filter = 
                    new Autodesk.AutoCAD.DatabaseServices.Filters.SpatialFilter())
                {
                    Autodesk.AutoCAD.DatabaseServices.Filters.SpatialFilterDefinition filterDef = 
                        new Autodesk.AutoCAD.DatabaseServices.Filters.SpatialFilterDefinition(ptCol, normal, elev, 0, 0, true);
                    filter.Definition = filterDef;

                    // Define the name of the extension dictionary and entry name
                    string dictName = "ACAD_FILTER";
                    string spName = "SPATIAL";

                    // Check to see if the Extension Dictionary exists, if not create it
                    if (acBlkRef.ExtensionDictionary.IsNull)
                    {
                        acBlkRef.CreateExtensionDictionary();
                    }

                    // Open the Extension Dictionary for write
                    DBDictionary extDict = acTrans.GetObject(acBlkRef.ExtensionDictionary, OpenMode.ForWrite) as DBDictionary;

                    // Check to see if the dictionary for clipped boundaries exists, 
                    // and add the spatial filter to the dictionary
                    if (extDict.Contains(dictName))
                    {
                        DBDictionary filterDict = acTrans.GetObject(extDict.GetAt(dictName), OpenMode.ForWrite) as DBDictionary;

                        if (filterDict.Contains(spName))
                        {
                            filterDict.Remove(spName);
                        }

                        filterDict.SetAt(spName, filter);
                    }
                    else
                    {
                        using (DBDictionary filterDict = new DBDictionary())
                        {
                            extDict.SetAt(dictName, filterDict);

                            acTrans.AddNewlyCreatedDBObject(filterDict, true);
                            filterDict.SetAt(spName, filter);
                        }
                    }

                    // Append the spatial filter to the drawing
                    acTrans.AddNewlyCreatedDBObject(filter, true);
                }
            }

            Application.ShowAlertDialog("The external reference is clipped.");
        }

        // Save the new objects to the database
        acTrans.Commit();

        // Dispose of the transaction
    }
}