Problem counting block references with GetBlockReferenceIds function
Accepted solution
Hi,
You may have a look at the Database.Purge(ObjectIdCollection ids) method.
Extract from the docs:
This function searches through the databse to see if there are any hard references to objects with object ID entities in the ids array. If any such objects are found, their object ID entities are removed from the ids array. So, when this function returns, the ids array will contain only object ID entities of objects that are not currently hard-referenced and thus can safely be erased.
Try this snippet, it works fine for me.
The PurgeBlocks method is called in a While loop to ensure purging nested blocks (if any).
using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.EditorInput;
using Autodesk.AutoCAD.Runtime;
using System.Linq;
namespace PurgeBlockSample
{
public class Commands
{
[CommandMethod("Test")]
public void Test()
{
Document doc = Application.DocumentManager.MdiActiveDocument;
Database db = doc.Database;
Editor ed = doc.Editor;
int cnt;
while ((cnt = PurgeBlocks(db)) > 0)
{
ed.WriteMessage("\nPurged: {0} block{1}", cnt, cnt > 1 ? "s" : "");
}
}
private int PurgeBlocks(Database db)
{
ObjectIdCollection ids;
using (Transaction tr = db.TransactionManager.StartTransaction())
{
BlockTable bt = (BlockTable)tr.GetObject(db.BlockTableId, OpenMode.ForRead);
ids = new ObjectIdCollection(bt.Cast<ObjectId>().ToArray());
db.Purge(ids);
foreach (ObjectId id in ids)
{
BlockTableRecord btr = (BlockTableRecord)tr.GetObject(id, OpenMode.ForWrite);
btr.Erase();
}
tr.Commit();
}
return ids.Count;
}
}
}
VB code:
Imports Autodesk.AutoCAD.ApplicationServices
Imports Autodesk.AutoCAD.DatabaseServices
Imports Autodesk.AutoCAD.EditorInput
Imports Autodesk.AutoCAD.Runtime
Namespace PurgeBlockSample
Public Class Commands
<CommandMethod("Test")> _
Public Sub Test()
Dim doc As Document = Application.DocumentManager.MdiActiveDocument
Dim db As Database = doc.Database
Dim ed As Editor = doc.Editor
While True
Dim cnt = PurgeAllblocks(db)
If cnt = 0 Then
Exit While
End If
ed.WriteMessage(vbLf + "Purged: {0} block{1}", cnt, IIf(cnt > 0, "s", ""))
End While
End Sub
Function PurgeAllBlocks(ByVal db As Database) As Integer
Dim cnt As Integer
Using tr As Transaction = db.TransactionManager.StartTransaction()
Dim ids As ObjectIdCollection = New ObjectIdCollection()
Dim bt As BlockTable = DirectCast(tr.GetObject(db.BlockTableId, OpenMode.ForRead), BlockTable)
For Each id As ObjectId In bt
ids.Add(id)
Next
db.Purge(ids)
cnt = ids.Count
For Each id As ObjectId In ids
Dim btr As BlockTableRecord = _
DirectCast(tr.GetObject(id, OpenMode.ForWrite), BlockTableRecord)
btr.Erase()
Next
tr.Commit()
End Using
Return cnt
End Function
End Class
End Namespace
