[VBA程序]：获得封闭多义线的型心

XDSoft

Getting the centroid of a closed polyline  
ID    35353  
Applies to:    AutoCAD Map
AutoCAD Map
AutoCAD Map 2000

This document is part of    Polyline   Regions   VBA   AutoCAD MAP Technical Newsletter - January 2000   Map Automation     

2. 
   
3. [FONT=courier new]
   
4. Question
   
5. How do I get the centroid of a closed polyline in AutoCAD Map 5 without
   
6. creating a topology?
   
7. Answer
   
8. You need to form a Region object from the polyline and then calculate the
   
9. centroid of the region. The Visual Basic code example that follows shows how
   
10. this is done.
    
11. 
    
12. 
    
13. Sub GetCentroid()
    
14. 
    
15. Dim Doc As AcadDocument
    
16. Dim Entity As AcadEntity
    
17. Dim Region As AcadRegion
    
18. Dim Polylist(0 To 0) As AcadEntity
    
19. Dim Entities As AcadModelSpace
    
20. Dim nPoly As Integer  'number of polylines
    
21. Dim i As Integer
    
22. Set Doc = ThisDrawing
    
23. Set Entities = Doc.ModelSpace
    
24. Dim Centroid As Variant
    
25. 
    
26. 
    
27. 
    
28. 'Form a region from each polyline
    
29. For Each Entity In Entities
    
30. 
    
31. If Entity.ObjectName = "AcDbPolyline" Then  'Polyline ?
    
32.     Set Polylist(0) = Entity
    
33.     Entities.AddRegion Polylist
    
34.    MsgBox Entity.ObjectName
    
35. End If
    
36.   
    
37. Next
    
38. 
    
39. 'Find centroid of each region
    
40. For i = 0 To Entities.Count - 1
    
41. 
    
42. If Entities.Item(i).ObjectName = "AcDbRegion" Then  'Region ?
    
43.     Set Region = Entities.Item(i)
    
44.     Centroid = Region.Centroid
    
45.     MsgBox "Centroid X: " & Centroid(0) & vbCrLf & "Centroid Y: " & Centroid(1)
    
46. End If
    
47.   
    
48. Next
    
49. 
    
50. 
    
51. End Sub
    
52. [/FONT]

<br /> [FONT=courier new]<br /> Question <br /> How do I get the centroid of a closed polyline in AutoCAD Map 5 without<br /> creating a topology?<br /> Answer <br /> You need to form a Region object from the polyline and then calculate the<br /> centroid of the region. The Visual Basic code example that follows shows how<br /> this is done.<br /> <br /> <br /> Sub GetCentroid()<br /> <br /> Dim Doc As AcadDocument<br /> Dim Entity As AcadEntity<br /> Dim Region As AcadRegion<br /> Dim Polylist(0 To 0) As AcadEntity<br /> Dim Entities As AcadModelSpace<br /> Dim nPoly As Integer  'number of polylines<br /> Dim i As Integer<br /> Set Doc = ThisDrawing<br /> Set Entities = Doc.ModelSpace<br /> Dim Centroid As Variant<br /> <br /> <br /> <br /> 'Form a region from each polyline<br /> For Each Entity In Entities<br /> <br /> If Entity.ObjectName = "AcDbPolyline" Then  'Polyline ?<br />     Set Polylist(0) = Entity<br />     Entities.AddRegion Polylist<br />    MsgBox Entity.ObjectName<br /> End If<br />   <br /> Next<br /> <br /> 'Find centroid of each region<br /> For i = 0 To Entities.Count - 1<br /> <br /> If Entities.Item(i).ObjectName = "AcDbRegion" Then  'Region ?<br />     Set Region = Entities.Item(i)<br />     Centroid = Region.Centroid<br />     MsgBox "Centroid X: " & Centroid(0) & vbCrLf & "Centroid Y: " & Centroid(1)<br /> End If<br />   <br /> Next<br /> <br /> <br /> End Sub<br /> [/FONT]