Performance issue Changing Color

I am re-writing a program that we use to convert DXF files we get from a client to our standards. This application was originally written for AutoCAD 14, but I have (with some help) re-written it in VB as a stand alone application for 2004. Everything work good accept on part. The intent was to hide AutoCAD and show only a progress bar as the application did it's thing. Loaded some linetypes, converted some of their standard layer names to our using our line types etc. The step I am having problems with is setting all entities color to 'ByLayer'.

The original simply used a command line method of selecting all objects in the drawing, then doing a 'change' , 'color', 'bylayer' That I ended up porting over like this...

Dim commandsend As String
commandsend = "Change" & vbCr & "all" & vbCr & vbCr & "p" & vbCr & "color" & vbCr & "Bylayer" & vbCr & vbCr
acad.ActiveDocument.SendCommand (commandsend)
acad.Visible = False

The issue with this method in the new application is that when sending a line to the command interpreter of AutoCAD it makes AutoCAD visible for some reason (why I had the 'acad.Visible = false' at the end to hide it again). But it's very quick. So you see a flash of AutoCAD as it does this step then its gone.

So in order to get around that I tried to bypass the command line with this... (Variable definitions not included)

i = 0
If sSet.Count > 0 Then
For Each oEnt In sSet
oEnt.Color = acByLayer
i = i + 1
Form1.Label4.Caption = "Processing: " & i & " of " & sSet.Count
Form1.Label4.Refresh
Next
End If

This works, but the issue is the process to change color this way takes a very long time in relation to the other.

Does anyone know a method of changing the color of all objects in a drawing other then using these two ways, or perhaps a flaw in my logic above that would solve my issue. Either making the first example, not show AutoCAD or the 2nd not take 1-2 minutes a drawing (some have 20k entities in them, taking time to loop through).

 

Comment these lines out and just change the caption once to something
like "Processing...". Form repaints are not exactly economical.

 

Your problem has nothing to do with form updates.

You are running an interprocess COM client. Cross-
process COM calls can take anywhere from 10-50X
longer than the equivalent from an in-process client
(e.g., loaded as a DLL in AutoCAD's process space).

To resolve this, you can do several things. One is
to build your entire application as an ActiveX DLL
that can be loaded by AutoCAD into its own process
space. Or, you can seperate the AutoCAD-intensive
portions of your application, and make them ActiveX
components housed in a DLL, that are loaded by the
main application, or you can go back to the sloppy
method of driving AutoCAD via the command line.

 

If you really like the dynamic caption, idea, use this to make it run
faster....

i = i + 1
' update label only every 100 iterations ... change # to suit your
taste
if i mod 100 = 0 then Form1.Label4.Caption = "Processing: " & i &
" of " & sSet.Count

James