创建复合区域 （.NET）

您可以通过减去、合并或查找区域或 3D 实体的交集来创建复合区域。然后，可以拉伸或旋转复合区域以创建复杂的实体。若要创建复合区域，请使用该方法。BooleanOperation

减去区域

当您从一个区域减去另一个区域时，从第一个区域调用该方法。这是您要从中减去的区域。例如，若要计算平面图需要多少地毯，请从楼层空间的外部边界调用该方法，并使用未铺地毯的区域（如柱子和柜台）作为布尔参数列表中的对象。BooleanOperationBooleanOperation

联合区域

若要统一区域，请调用该方法并使用常量进行操作，而不是 。您可以按任意顺序组合区域以统一它们。BooleanOperationBooleanOperationType.BoolUniteBooleanOperationType.BoolSubtract

找到两个区域的交集

要查找两个区域的交集，请使用常量。您可以按任意顺序组合区域以使其相交。BooleanOperationType.BoolIntersect

创建复合区域

下面的示例从两个圆中创建两个区域，然后从大圆中减去较小的区域以创建一个轮子。

Imports Autodesk.AutoCAD.Runtime
Imports Autodesk.AutoCAD.ApplicationServices
Imports Autodesk.AutoCAD.DatabaseServices
Imports Autodesk.AutoCAD.Geometry
 
<CommandMethod("CreateCompositeRegions")> _
Public Sub CreateCompositeRegions()
    '' 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 two in memory circles
        Using acCirc1 As Circle = New Circle()
            acCirc1.Center = New Point3d(4, 4, 0)
            acCirc1.Radius = 2

            Using acCirc2 As Circle = New Circle()
                acCirc2.Center = New Point3d(4, 4, 0)
                acCirc2.Radius = 1

                '' Adds the circle to an object array
                Dim acDBObjColl As DBObjectCollection = New DBObjectCollection()
                acDBObjColl.Add(acCirc1)
                acDBObjColl.Add(acCirc2)

                '' Calculate the regions based on each closed loop
                Dim myRegionColl As DBObjectCollection = New DBObjectCollection()
                myRegionColl = Region.CreateFromCurves(acDBObjColl)
                Dim acRegion1 As Region = myRegionColl(0)
                Dim acRegion2 As Region = myRegionColl(1)

                '' Subtract region 1 from region 2
                If acRegion1.Area > acRegion2.Area Then
                    '' Subtract the smaller region from the larger one
                    acRegion1.BooleanOperation(BooleanOperationType.BoolSubtract, acRegion2)
                    acRegion2.Dispose()

                    '' Add the final region to the database
                    acBlkTblRec.AppendEntity(acRegion1)
                    acTrans.AddNewlyCreatedDBObject(acRegion1, True)
                Else
                    '' Subtract the smaller region from the larger one
                    acRegion2.BooleanOperation(BooleanOperationType.BoolSubtract, acRegion1)
                    acRegion1.Dispose()

                    '' Add the final region to the database
                    acBlkTblRec.AppendEntity(acRegion2)
                    acTrans.AddNewlyCreatedDBObject(acRegion2, True)
                End If

                '' Dispose of the in memory objects not appended to the database
            End Using
        End Using

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

using Autodesk.AutoCAD.Runtime;
using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.Geometry;
 
[CommandMethod("CreateCompositeRegions")]
public static void CreateCompositeRegions()
{
    // 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 two in memory circles
        using (Circle acCirc1 = new Circle())
        {
            acCirc1.Center = new Point3d(4, 4, 0);
            acCirc1.Radius = 2;

            using (Circle acCirc2 = new Circle())
            {
                acCirc2.Center = new Point3d(4, 4, 0);
                acCirc2.Radius = 1;

                // Adds the circle to an object array
                DBObjectCollection acDBObjColl = new DBObjectCollection();
                acDBObjColl.Add(acCirc1);
                acDBObjColl.Add(acCirc2);

                // Calculate the regions based on each closed loop
                DBObjectCollection myRegionColl = new DBObjectCollection();
                myRegionColl = Region.CreateFromCurves(acDBObjColl);
                Region acRegion1 = myRegionColl[0] as Region;
                Region acRegion2 = myRegionColl[1] as Region;

                // Subtract region 1 from region 2
                if (acRegion1.Area > acRegion2.Area)
                {
                    // Subtract the smaller region from the larger one
                    acRegion1.BooleanOperation(BooleanOperationType.BoolSubtract, acRegion2);
                    acRegion2.Dispose();

                    // Add the final region to the database
                    acBlkTblRec.AppendEntity(acRegion1);
                    acTrans.AddNewlyCreatedDBObject(acRegion1, true);
                }
                else
                {
                    // Subtract the smaller region from the larger one
                    acRegion2.BooleanOperation(BooleanOperationType.BoolSubtract, acRegion1);
                    acRegion1.Dispose();

                    // Add the final region to the database
                    acBlkTblRec.AppendEntity(acRegion2);
                    acTrans.AddNewlyCreatedDBObject(acRegion2, true);
                }

                // Dispose of the in memory objects not appended to the database
            }
        }

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

Sub CreateCompositeRegions()
    ' Create two circles, one representing outside of the wheel,
    ' the other the center of the wheel
    Dim DonutParts(0 To 1) As AcadCircle
    Dim center(0 To 2) As Double
    Dim radius As Double
    center(0) = 4
    center(1) = 4
    center(2) = 0
    radius = 2#
    Set WheelParts(0) = ThisDrawing.ModelSpace. _
                            AddCircle(center, radius)
    radius = 1#
    Set WheelParts(1) = ThisDrawing.ModelSpace. _
                            AddCircle(center, radius)
 
    ' Create a region from the two circles
    Dim regions As Variant
    regions = ThisDrawing.ModelSpace.AddRegion(WheelParts)
 
    ' Copy the regions into the region variables for ease of use
    Dim WheelOuter As AcadRegion
    Dim WheelInner As AcadRegion
 
    If regions(0).Area > regions(1).Area Then
        ' The first region is the outer edge of the wheel
        Set WheelOuter = regions(0)
        Set WheelInner = regions(1)
    Else
        ' The first region is the inner edge of the wheel
        Set WheelInner = regions(0)
        Set WheelOuter = regions(1)
    End If
 
    ' Subtract the smaller circle from the larger circle
    WheelOuter.Boolean acSubtraction, WheelInner
End Sub