AcadXCurve.Trim - Tony?

OK, I give up. How in the heck do you get this to work? I've been messing
aroung with it for hours, and no matter what I do, I get an error "Object
does not support this method". My selection set is filtered for only the
AcadObjects allowed (and my test drawing only has lines anyway) and
"cutLine" is a valid AcadLine. This is the part of the code that fails:

Dim ent As New AcadXCurve
Dim x As Long
Dim cutPt As Variant
For x = 0 To trimSS.Count - 1
ent.Entity = trimSS.Item(x) 'OK, I can verify in Locals window
cutPt = ent.IntersectWith(cutLine, acExtendNone) ' OK, returns
valid cutPt
ent.Trim cutLine, cutPt ' nope, errors out
Next x

Any ideas?

Jeff

 

Don't use Trim(). You need to use Break(), and then just
manally erase the fragments you don't want. When I begin
implementing Trim, I realized that the TRIM command was a
UI-centric operation that relies on a selection point (in
the DCS!) to determine what part(s) of the object are to
be removed. I also realized that trying to implement a
fully programmatic equivalent was a bit more work than I
had expected.

Break() gives you the option of determining what to keep
and what to discard, using any means you choose. In fact,
you can easily implement your own Trim by just breaking
the object at the points where it intersects the cutting
edge, and then use the selection point or some other
criteria to determine which of the resulting fragments
you want to keep or discard.

To see an example of this, look at CUT.LSP.