Use an Open LW Polyline as the Boundary for a Hatch in VBA

by Fenton Webb

Issue

How can I use a lightweight polyline that is open to define the boundary for a
new hatch entity? Can I also use the AddVertex method for adding vertexes to the
lightweight polyline?

Solution

The following code contains a function that creates a lightweight polyline
(using AddVertex) that is left "open" (although its start and end points
coincide). This polyline is then used in the outerloop of the hatch entity
created below.

Option Base 0

Sub TestLWPline ()
   ‘build the initial array for two points
   Dim Pt(0 To 3) As Double
   Pt(0) = 0#: Pt(1) = 0#: Pt(2) = 0#: Pt(3) = 10#
   ‘create a lwpline based on the two points
   Dim LWpline As Object
   Set LWpline = ThisDrawing.ModelSpace.AddLightWeightPolyline(Pt)
   ‘add further points
   Pt(0) = 10#: Pt(1) = 10#
   LWpline.AddVertex 2, Pt
   ‘add a the start point to lwpline again so
   ‘that the start and end points coincide but its Closed
   ‘property is false
   Pt(0) = 0#: Pt(1) = 0#
   LWpline.AddVertex 3, Pt
   ‘you can check here if it is really false
   Dim bClosed As Boolean
   bClosed = LWpline.closed
   ‘add a hatch to modelspace
   Dim MyHatch As Object
   Set MyHatch = ThisDrawing.ModelSpace.AddHatch

(acHatchPatternTypePreDefined,"ANSI31", True)
   ‘create and append outer loop
   Dim outerLoop As Variant

   Dim outerLoopArray(0) As Object
   Set outerLoopArray(0) = LWpline

   outerLoop = outerLoopArray
   MyHatch.AppendOuterLoop (outerLoop)

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p style=”margin: 0px 0px 15px;line-height: 16px”>End Sub