Use the Explode method to break a block reference. By exploding a block ref-erence, you can modify the block or add to or delete the objects that define it.
Display the results of an exploded block reference
This example creates a block and adds a circle to the definition of the block. The block is then inserted into the drawing as a block reference. The block reference is then exploded, and the objects resulting from the explode process are displayed along with their object types.
Sub Ch10_ExplodingABlock()
' Define the block
Dim blockObj As AcadBlock
Dim insertionPnt(0 To 2) As Double
insertionPnt(0) = 0
insertionPnt(1) = 0
insertionPnt(2) = 0
Set blockObj = ThisDrawing.Blocks.Add _
(insertionPnt, "CircleBlock")
' Add a circle to the block
Dim circleObj As AcadCircle
Dim center(0 To 2) As Double
Dim radius As Double
center(0) = 0
center(1) = 0
center(2) = 0
radius = 1
Set circleObj = blockObj.AddCircle(center, radius)
' Insert the block
Dim blockRefObj As AcadBlockReference
insertionPnt(0) = 2
insertionPnt(1) = 2
insertionPnt(2) = 0
Set blockRefObj = ThisDrawing.ModelSpace.InsertBlock _
(insertionPnt, "CircleBlock", 1#, 1#, 1#, 0)
ZoomAll
MsgBox "The circle belongs to " & blockRefObj.ObjectName
' Explode the block reference
Dim explodedObjects As Variant
explodedObjects = blockRefObj.Explode
' Loop through the exploded objects
Dim I As Integer
For I = 0 To UBound(explodedObjects)
explodedObjects(I).Color = acRed
explodedObjects(I).Update
MsgBox "Exploded Object " & I & ": " _
& explodedObjects(I).ObjectName
explodedObjects(I).Color = acByLayer
explodedObjects(I).Update
Next
End Sub