§建立对象之间的关系
§如: 门或窗放置在墙上,墙移动, 门和窗随之移动
§存储在数据库对象
§许多派生类,主要派生关系图如下:
•Anchor
• AnchorToReference
• AnchorEntityToCurve
§检查一个对象是否有Anchor
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§2a - Aec Basics.vb > TestAnchor command
Dim geo As
Geo = tr.GetObject(geoId, OpenMode.ForRead)
If
geo.AnchorId.IsNull Then
' Not
anchored
Else
Dim anchor As Anchor =
tr.GetObject(geo.AnchorId, OpenMode.ForRead)
' Further check anchor
type...
End If