Anchor a tag to an entity

By Mikako Harada

Issue

I want to anchor a tag to an entity.  I used AnchorTagToEntity. But it behaves differently. I want to make the tag behaves like a door tag added by the UI. How can I do that?  

Solution

ACA uses AnchorExtendedTagToEntity to anchor a tag. It has extra functionality to the AnchorTagToEntity, for example, a tag moves together when the anchored object (e.g., a door) moves, keeping the same distance. The below is a sample code that demonstrates how to add the anchor. For simplicity, I'm assuming that the tag object is in the drawing already.

' Anchor a tag to an entity. 
 
   _
  Public Sub anchorExtendedTagToEnt()
 
    Dim doc As Document =
      Application.DocumentManager.MdiActiveDocument
    Dim ed As Editor = doc.Editor
    Dim db As Database = doc.Database
 
    ' (1) select a Geo 
    ' Geo is a base class for AEC objects. 
 
    Dim optGeo As New PromptEntityOptions(
      "Select a geo to anchor a tag")
    optGeo.SetRejectMessage("Not a geo")
    optGeo.AddAllowedClass(GetType(Geo), False)
 
    Dim resGeo As PromptEntityResult = ed.GetEntity(optGeo)
    If resGeo.Status  PromptStatus.OK Then
      ed.WriteMessage("failed to pick an geo")
      Exit Sub
    End If
 
    Dim idGeo As ObjectId = resGeo.ObjectId
 
    ' (2) Select a tag 
 
    Dim optTag As New PromptEntityOptions("Select a tag ")
    optTag.SetRejectMessage("Not a tag")
    optTag.AddAllowedClass(GetType(MultiViewBlockReference), True)
 
    Dim resTag As PromptEntityResult = ed.GetEntity(optTag)
    If resTag.Status  PromptStatus.OK Then
      ed.WriteMessage("failed to pick a tag")
      Exit Sub
    End If
 
    Dim idTag As ObjectId = resTag.ObjectId
 
    ' (3) Pick a location to place the tag
 
    Dim resPt As PromptPointResult =
      ed.GetPoint("Pick a location of the tag ")
    If resPt.Status  PromptStatus.OK Then
      ed.WriteMessage("failed to pick a location of the tag")
      Exit Sub
    End If
 
    ' (4) Add a tag to the geo using AnchorExtendedTagToEntity  
 
    Dim trans As Transaction =
      db.TransactionManager.StartTransaction()
 
    Try
      ' Open the geo for read 
 
      Dim obj As Object = trans.GetObject(idGeo, OpenMode.ForRead)
      Dim objGeo As Geo = CType(obj, Geo)
      Dim ecsEnt As Matrix3d = objGeo.Ecs()
 
      ' Oopen the tag for write 
 
      obj = trans.GetObject(idTag, OpenMode.ForWrite)
      Dim objTag As MultiViewBlockReference =
        CType(obj, MultiViewBlockReference)
 
      ' Adjust the location of the tag 
 
      Dim pt As Point3d = resPt.Value
      objTag.Location = pt.TransformBy(ecsEnt.Inverse())
 
      ' Add an anchor between the tag and the geo 
 
      Dim pAnchor As New AnchorExtendedTagToEntity
      pAnchor.SubSetDatabaseDefaults(db)
      pAnchor.SetToStandard(db)
 
      pAnchor.ForceHorizontal = False '' or True
 
      ' Here is the main part that attaches the tag to the geo 
      ' entity (e.g., door and window) 
 
      pAnchor.ReferencedEntityId = idGeo
      objTag.SetAnchor(pAnchor)
 
      trans.Commit()
 
    Catch ex As Exception
      trans.Abort()
    Finally
      trans.Dispose()
    End Try
 
  End Sub