217 Posts
1 Kudo
Registered: ‎08-24-2010
Post 1 of 4

different Between Database definitions

279 Views, 3 Replies
04-22-2013 03:17 AM

what's the different between


 Dim oDb As Database = HostApplicationServices.WorkingDatabase



Dim oDb As Database = Application.DocumentManager.MdiActiveDocument.Database


Dim oDb As Database = Application.DocumentManager.MdiActiveDocument.Editor.Document.Database


Valued Mentor
370 Posts
175 Kudos
Registered: ‎05-06-2012
Post 2 of 4

Re: different Between Database definitions

04-22-2013 06:26 AM in reply to: Amremad

In AutoCAD they return the same value.


HostApplicationServices is a way to access certain functions in non-AutoCAD host applications (e.g,. RealDWG), where there is no Document object.

225 Posts
24 Kudos
Registered: ‎09-15-2011
Post 3 of 4

Re: different Between Database definitions

04-22-2013 07:17 AM in reply to: Amremad

Autodesk.AutoCAD.ApplicationServices.Application is a class from assembly acmgd.dll which references acdbmgd.dll


Autodesk.AutoCAD.DatabaseServices.HostApplicationServices is a class from acdbmgd.dll


Autodesk.AutoCAD.DatabaseServices.HostApplicationServices.WorkingDatabase is the active working database of the single-threaded RealDWG process, which is an engine of AutoCAD without UI.


In AutoCAD, Autodesk.AutoCAD.DatabaseServices.HostApplicationServices.WorkingDatabase is a pointer of Autodesk.AutoCAD.ApplicationServices.Application.DocumentManager.MdiActiveDocument.Database. So every time you change the active drawing on AutoCAD, it will set MdiActiveDocument.Database to WorkingDatabase. There are many MdiActiveDocument.Databases in DocumentManager, but there is only one WorkingDatabase which is a worker of MdiActiveDocument.Database.


In short, all AutoCAD database tasks are based on RealDWG engine, MdiActiveDocument.Database is an upper layer of WorkingDatabase.


You also see the another answer at the link.





225 Posts
24 Kudos
Registered: ‎09-15-2011
Post 4 of 4

Re: different Between Database definitions

04-22-2013 07:31 AM in reply to: Amremad

In short, in AutoCAD:
Application.DocumentManager.MdiActiveDocument.Database calls HostApplicationServices.WorkingDatabase to execute the drawing database job.

MdiActiveDocument.Editor.Document = MdiActiveDocument so MdiActiveDocument.Editor.Document.Database = MdiActiveDocument.Database

In RealDWG, there is only HostApplicationServices.WorkingDatabase

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