By Adam Nagy
Through the user interface you can query the length of an entity loop using the Measure Loop tool (Tools >> Measure >> Loop)
If you want to keep showing the length of a specific loop, e.g. in the sketch environment, while editing the geometry, you can do that from your AddIn or VBA. In this case I created a form class in VBA called LengthForm, with a Label (named LengthValue) and a Button (named MarkEntity) on it and used the following code.
Note that this part of the code is for the form that you've just created. Right-click on the LengthForm in the Project window's tree and select View Code - that's where this code should be pasted.
Private WithEvents docEvents As DocumentEvents Private selEnt As Object Private Sub docEvents_OnChange( _ ByVal ReasonsForChange As CommandTypesEnum, _ ByVal BeforeOrAfter As EventTimingEnum, _ ByVal Context As NameValueMap, _ HandlingCode As HandlingCodeEnum) If BeforeOrAfter <> kAfter Then Exit Sub LengthValue.Caption = GetLength(selEnt) End Sub Private Sub MarkEntity_Click() Dim ss As SelectSet Set ss = ThisApplication.ActiveDocument.SelectSet If ss.Count = 0 Then Set docEvents = Nothing LengthValue.Caption = "" Else Set docEvents = _ ThisApplication.ActiveDocument.DocumentEvents Set selEnt = ss(1) LengthValue.Caption = GetLength(selEnt) End If End Sub Function GetLength(ent As Object) As String Dim l As Double ' Try this 'l = ThisApplication.MeasureTools.GetLoopLength(ent) ' Or this l = GetFirstLoopLength(ent) ' Internal length unit is cm GetLength = str(l) + " cm" End Function ' This is using own logic Function GetFirstLoopLength(ByVal ent As SketchEntity) As Double If ent Is Nothing Then Exit Function Dim ents As ObjectCollection Set ents = ThisApplication.TransientObjects.CreateObjectCollection Call ents.Add(ent) Dim success As Boolean success = GetFirstLoopRec(ent, ent.EndSketchPoint, ents) If success Then Dim l As Double For Each ent In ents l = l + ent.Length Next GetFirstLoopLength = l End If End Function ' Return True means we're done Function GetFirstLoopRec(prev As SketchEntity, sp As SketchPoint, _ ents As ObjectCollection) As Boolean Dim first As Object Set first = ents(1) Dim ent As SketchLine For Each ent In sp.OwnedBy ' If it's not the same as the previuos ' entity If Not ent Is prev Then ' If it's the same as the first entity ' then we made a loop If ent Is first Then GetFirstLoopRec = True Exit Function End If Call ents.Add(ent) ' Get the sketch point on the other ' side of this entity If ent.StartSketchPoint Is sp Then If GetFirstLoopRec( _ ent, ent.EndSketchPoint, ents) Then GetFirstLoopRec = True Exit Function End If Else If GetFirstLoopRec( _ ent, ent.StartSketchPoint, ents) Then GetFirstLoopRec = True Exit Function End If End If End If Next GetFirstLoopRec = False End Function
Now I can show it modelessly, so that it is always visible.
Dim lf As LengthForm Sub ShowLengthForm() Set lf = New LengthForm lf.Show vbModeless End Sub
When testing the code, first select a sketch entity that is part of a loop, and then click Mark Entity.