very easy issue of polyline but can't get it working

Hi Guys, I am trying to so something super simple. I have a list of 3dpoints input into my VB script and I want to join them into a polyline. The points are sorted already, so they won't intersect and should join fine.

I thought this problem is as simple as one or two line, but it always gives me errors. Here's the code:

Private Sub RunScript(ByVal pts As List(Of Point3d), ByRef A As Object)

Dim hex As Polyline(pts)

End Sub

the error msg is: array bounds cannot appear in type specifiers. What does this mean? And anyone has the solution to this problem?

Thanks a lot for all of your help!

Replies to This Discussion

Permalink Reply by David Rutten on March 20, 2011 at 2:37pm

Hi Fan,

VB uses the same kind of bracket for arrays and function calls. I've always found this one of the stupidest features of the language. The way you declare your variable:

Dim hex As Polyline(pts)

is interpreted by VB as "I'll create an array of Polylines, stored in a variable called 'hex' which contains pts polylines". It complains because you're not supposed to set a definite size when you declare an array like this.

What you wanted to do though is create a NEW polyline which connects a bunch of points. If you insert the New keyword, this code will work:

Dim hex As New Polyline(pts)

Now, the brackets mean something else. The New keyword means you're calling a Constructor of the Polyline class now. A Constructor is a special function that gets called only once and always immediately when an instance of a class is first created. So in this case the brackets indicate a function call.

David Rutten

david@mcneel.com

Poprad, Slovakia

Permalink Reply by Fan Zhang on March 20, 2011 at 3:49pm