如何获得类型为polyline的闭合二维多段线的面积

changyiran

我在用vla-get-area方法获取时，提示“错误: Automation 错误。 类无效”，然后用(vlax-dump-Object vla)查了下，信息如下：
; IAcadLWPolyline: AutoCAD Lightweight Polyline 接口
;特性值:
;   Application (RO) = #<VLA-OBJECT IAcadApplication 00b5e51c>
;   Area (RO) = AutoCAD.Application: 类无效
;   Closed = AutoCAD.Application: 类无效
;   ConstantWidth = AutoCAD.Application: 类无效
;   Coordinate = ...不显示带索引的内容...
;   Coordinates = AutoCAD.Application: 类无效
;   Document (RO) = #<VLA-OBJECT IAcadDocument 01e226b0>
;   Elevation = AutoCAD.Application: 类无效
;   Handle (RO) = "43C"
;   HasExtensionDictionary (RO) = 0
;   Hyperlinks (RO) = #<VLA-OBJECT IAcadHyperlinks 03720e34>
;   Layer = "JZD"
;   Length (RO) = AutoCAD.Application: 类无效
;   Linetype = "CONTINUOUS"
;   LinetypeGeneration = AutoCAD.Application: 类无效
;   LinetypeScale = 1.0
;   Lineweight = -1
;   Normal = AutoCAD.Application: 类无效
;   ObjectID (RO) = 2130115616
;   ObjectName (RO) = "AcDb2dPolyline"
;   OwnerID (RO) = 2130107584
;   PlotStyleName = "ByLayer"
;   Thickness = AutoCAD.Application: 类无效
;   TrueColor = #<VLA-OBJECT IAcadAcCmColor 03720d20>
;   Visible = -1
T
area特性确实是无效的，那这种情况下该如何获取其面积呢？还望高手们指教下！

changyiran

各位版主帮帮忙啊，这个没法搞定吗？

zzyong00

1. Option Explicit
   
2. 
   
3. 
   
4. Public Sub SelectSinglePLine(returnObj As AcadPolyline, _
   
5.     basePnt As Variant, _
   
6.     blnESC As Boolean)
   
7.    
   
8.     On Error Resume Next
   
9.     'If ThisDrawing.GetVariable("cmdactive") Then ThisDrawing.SendCommand "(command)" & vbCrLf
   
10.     ' The following example waits for a selection from the user
    
11. RETRY:
    
12.     ThisDrawing.Utility.GetEntity returnObj, basePnt, "请选择任意一条多线段："
    
13.    
    
14.     'Debug.Print Err.Number, Err.Description
    
15.     If Err.Number = -2147352567 Then
    
16.         blnESC = True
    
17.         Exit Sub
    
18.     End If
    
19.    
    
20.     If Err <> 0 Then
    
21.         Err.Clear
    
22.         GoTo RETRY
    
23.     Else
    
24.         returnObj.Highlight True
    
25.         'MsgBox "The object type is: " & returnObj.EntityName, , "GetEntity 示例"
    
26.         ' returnObj.Update
    
27.     End If
    
28.    
    
29. End Sub
    
30. 
    
31. 
    
32. Public Sub ss()
    
33. Dim returnObj As AcadPolyline, basePnt As Variant, blnESC As Boolean
    
34. SelectSinglePLine returnObj, basePnt, blnESC
    
35. Debug.Print returnObj.Area
    
36. End Sub
    

Option Explicit<br /> <br /> <br /> Public Sub SelectSinglePLine(returnObj As AcadPolyline, _<br />     basePnt As Variant, _<br />     blnESC As Boolean)<br />     <br />     On Error Resume Next<br />     'If ThisDrawing.GetVariable("cmdactive") Then ThisDrawing.SendCommand "(command)" & vbCrLf<br />     ' The following example waits for a selection from the user<br /> RETRY:<br />     ThisDrawing.Utility.GetEntity returnObj, basePnt, "请选择任意一条多线段："<br />     <br />     'Debug.Print Err.Number, Err.Description<br />     If Err.Number = -2147352567 Then<br />         blnESC = True<br />         Exit Sub<br />     End If<br />     <br />     If Err <> 0 Then<br />         Err.Clear<br />         GoTo RETRY<br />     Else<br />         returnObj.Highlight True<br />         'MsgBox "The object type is: " & returnObj.EntityName, , "GetEntity 示例"<br />         ' returnObj.Update<br />     End If<br />     <br /> End Sub<br /> <br /> <br /> Public Sub ss()<br /> Dim returnObj As AcadPolyline, basePnt As Variant, blnESC As Boolean<br /> SelectSinglePLine returnObj, basePnt, blnESC<br /> Debug.Print returnObj.Area<br /> End Sub<br />

我用vba测试，没有任何问题呀

changyiran

zzyong00 发表于 2015-4-13 08:49
我用vba测试，没有任何问题呀

vba没用过，不太清楚，但是vlisp确实获取不了。不知为何