用C#开发CAD2016插件 用region对象分割多段线的代码示例

以下是用region对象分割多段线的C#代码示例：

using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.Geometry;

public void SplitPolylineByRegion(Polyline polyline, Region region)
{
    Database db = HostApplicationServices.WorkingDatabase;
    using (Transaction tr = db.TransactionManager.StartTransaction())
    {
        BlockTableRecord btr = (BlockTableRecord)tr.GetObject(db.CurrentSpaceId, OpenMode.ForWrite);
        bool isInsideRegion = false;
        Point3dCollection points = new Point3dCollection();
        for (int i = 0; i < polyline.NumberOfVertices; i++)
        {
            Point3d point = polyline.GetPoint3dAt(i);
            if (region.IsPointInside(point, Vector3d.ZAxis))
            {
                if (!isInsideRegion)
                {
                    if (points.Count > 1)
                    {
                        Polyline newPolyline = new Polyline(points.Count);
                        for (int j = 0; j < points.Count; j++)
                        {
                            newPolyline.AddVertexAt(j, points[j], 0, 0, 0);
                        }
                        btr.AppendEntity(newPolyline);
                        tr.AddNewlyCreatedDBObject(newPolyline, true);
                    }
                    points = new Point3dCollection();
                }
                isInsideRegion = true;
            }
            else
            {
                if (isInsideRegion)
                {
                    points.Add(point);
                }
                isInsideRegion = false;
            }
        }
        if (points.Count > 1)
        {
            Polyline newPolyline = new Polyline(points.Count);
            for (int j = 0; j < points.Count; j++)
            {
                newPolyline.AddVertexAt(j, points[j], 0, 0, 0);
            }
            btr.AppendEntity(newPolyline);
            tr.AddNewlyCreatedDBObject(newPolyline, true);
        }
        tr.Commit();
    }
}

这个方法接受两个参数，一个是多段线对象，另一个是region对象。方法会遍历多段线的所有顶点，判断每个顶点是否在region内部。如果顶点在region内部，就将其添加到新的多段线中；如果顶点不在region内部，就将之前的顶点组成的多段线添加到图形数据库中，并开始新的多段线。

注意，此代码示例仅供参考，并不保证在所有情况下都能正常工作。您需要根据具体的项目需求进行调整和优化。