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ObjectARX 开发指南

擦除对象（.NET）

2023-1-1 14:08| 发布者: admin| 查看: 646| 评论: 0|来自: AutoCAD

您可以使用该方法删除非图形和图形对象。Erase

谨慎：虽然许多非图形对象（如图层表和模型空间块表记录）具有方法，但不应调用该方法。如果在其中一个对象上调用，则会发生错误。EraseErase

创建和擦除折线

本示例创建轻量级折线，然后擦除它。

VB.NET

Imports Autodesk.AutoCAD.Runtime
Imports Autodesk.AutoCAD.ApplicationServices
Imports Autodesk.AutoCAD.DatabaseServices
Imports Autodesk.AutoCAD.Geometry
 
<CommandMethod("EraseObject")> _
Public Sub EraseObject()
    '' Get the current document and database
    Dim acDoc As Document = Application.DocumentManager.MdiActiveDocument
    Dim acCurDb As Database = acDoc.Database

    '' Start a transaction
    Using acTrans As Transaction = acCurDb.TransactionManager.StartTransaction()

        '' Open the Block table for read
        Dim acBlkTbl As BlockTable
        acBlkTbl = acTrans.GetObject(acCurDb.BlockTableId, OpenMode.ForRead)

        '' Open the Block table record Model space for write
        Dim acBlkTblRec As BlockTableRecord
        acBlkTblRec = acTrans.GetObject(acBlkTbl(BlockTableRecord.ModelSpace), _
                                        OpenMode.ForWrite)

        '' Create a lightweight polyline
        Using acPoly As Polyline = New Polyline()
            acPoly.AddVertexAt(0, New Point2d(2, 4), 0, 0, 0)
            acPoly.AddVertexAt(1, New Point2d(4, 2), 0, 0, 0)
            acPoly.AddVertexAt(2, New Point2d(6, 4), 0, 0, 0)

            '' Add the new object to the block table record and the transaction
            acBlkTblRec.AppendEntity(acPoly)
            acTrans.AddNewlyCreatedDBObject(acPoly, True)

            '' Update the display and display an alert message
            acDoc.Editor.Regen()
            Application.ShowAlertDialog("Erase the newly added polyline.")

            '' Erase the polyline from the drawing
            acPoly.Erase(True)
        End Using

        '' Save the new object to the database
        acTrans.Commit()
    End Using
End Sub

C#

using Autodesk.AutoCAD.Runtime;
using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.DatabaseServices;
 
[CommandMethod("EraseObject")]
public static void EraseObject()
{
    // Get the current document and database
    Document acDoc = Application.DocumentManager.MdiActiveDocument;
    Database acCurDb = acDoc.Database;

    // Start a transaction
    using (Transaction acTrans = acCurDb.TransactionManager.StartTransaction())
    {
        // Open the Block table for read
        BlockTable acBlkTbl;
        acBlkTbl = acTrans.GetObject(acCurDb.BlockTableId,
                                        OpenMode.ForRead) as BlockTable;

        // Open the Block table record Model space for write
        BlockTableRecord acBlkTblRec;
        acBlkTblRec = acTrans.GetObject(acBlkTbl[BlockTableRecord.ModelSpace],
                                        OpenMode.ForWrite) as BlockTableRecord;

        // Create a lightweight polyline
        using (Polyline acPoly = new Polyline())
        {
            acPoly.AddVertexAt(0, new Point2d(2, 4), 0, 0, 0);
            acPoly.AddVertexAt(1, new Point2d(4, 2), 0, 0, 0);
            acPoly.AddVertexAt(2, new Point2d(6, 4), 0, 0, 0);

            // Add the new object to the block table record and the transaction
            acBlkTblRec.AppendEntity(acPoly);
            acTrans.AddNewlyCreatedDBObject(acPoly, true);

            // Update the display and display an alert message
            acDoc.Editor.Regen();
            Application.ShowAlertDialog("Erase the newly added polyline.");

            // Erase the polyline from the drawing
            acPoly.Erase(true);
        }

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

VBA/ActiveX 代码参考

Sub EraseObject()
    ' Create the polyline
    Dim lwpolyObj As AcadLWPolyline
    Dim vertices(0 To 5) As Double
    vertices(0) = 2: vertices(1) = 4
    vertices(2) = 4: vertices(3) = 2
    vertices(4) = 6: vertices(5) = 4
    Set lwpolyObj = ThisDrawing.ModelSpace. _
                                     AddLightWeightPolyline(vertices)
    ZoomAll
    ' Erase the polyline
    lwpolyObj.Delete
    ThisDrawing.Regen acActiveViewport
End Sub