About Extending and Trimming Objects (VBA/ActiveX)

You can change the angle of arcs and you can change the length of open lines, arcs, open polylines, elliptical arcs, and open splines. The results are similar to both extending and trimming objects.

You can extend or trim an object by editing its properties. For example, to lengthen a line, simply change the coordinates of the StartPoint or EndPoint properties. To change the angle of an arc, change the StartAngle or EndAngle property of the arc. Once you have altered an object's property or properties, use the Update method to see your changes in the drawing.

Lengthen a line

This example creates a line and then changes the endpoint of that line, resulting in a longer line. 

Sub Ch4_LengthenLine()
  ' Define and create the line
  Dim lineObj As AcadLine
  Dim startPoint(0 To 2) As Double
  Dim endPoint(0 To 2)  As Double
  startPoint(0) = 0
  startPoint(1) = 0
  startPoint(2) = 0
  endPoint(0) = 1
  endPoint(1) = 1
  endPoint(2) = 1
  Set lineObj = ThisDrawing.ModelSpace.AddLine(startPoint, endPoint)
  lineObj.Update

  ' Lengthen the line by changing the
  ' endpoint to 4, 4, 4
  endPoint(0) = 4
  endPoint(1) = 4
  endPoint(2) = 4
  lineObj.endPoint = endPoint
  lineObj.Update
End Sub

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