proe二次开发：装配添加约束求救

mydear

现在我在装配体里面有一个圆柱体，我现在通过程序将另外一个圆柱体添加进来并进行约束添加，添加进来了，但是我在添加约束的时候老是发生异常，我把代码贴出来大家看看帮帮忙吧。
9 P$ p4 a/ `" B  p& Q  P4 @        Dim model As IpfcModel
, g( U' c3 r( l, Y7 V9 R9 ~        model = session.CurrentModel
        Dim assembly As IpfcAssembly
9 k$ v+ `. Y& ^: k! U        assembly = CType(model, IpfcAssembly)
  H5 z0 Z0 v: r! C8 C. r( X
        MsgBox(CType(assembly, IpfcSolid).ListFeaturesByType(True, EpfcFeatureType.EpfcFEATTYPE_DATUM_AXIS).Count.ToString())
( {; o& P3 G9 Q0 `5 n        'MsgBox(CType(assembly, IpfcModelItemOwner).ListItems(EpfcModelItemType.EpfcITEM_AXIS).Count.ToString())
! x; d! P5 B& Z9 `4 b
        Dim models As IpfcModels
        models = session.ListModels()
9 D. L5 r& }! h1 D* {        Dim asmmodelitemowner As IpfcModelItemOwner
% y/ e9 s/ Q: m3 D2 G3 X4 f& V        asmmodelitemowner = CType(models(1), IpfcModelItemOwner)//获取到原先已经添加进来的圆柱作为modelitemowner

: s& ~# V6 G6 U* k        Dim compmodelitemowner As IpfcModelItemOwner
        compmodelitemowner = CType(componentModel, IpfcModelItemOwner)//后来添加的圆柱owner
, H* Y6 G  a7 @% x0 h        Dim asmitem As IpfcModelItem
7 |* k7 I  T' l        Dim compitem As IpfcModelItem
        Try
  y0 u( k. ?! h            asmitem = asmmodelitemowner.GetItemById(EpfcModelItemType.EpfcITEM_AXIS, Convert.ToInt32(assemblyitemID))//通过id获取我所选择的圆柱的中心轴。
* V3 ~. L- w2 m( C! {4 S: v6 A9 K5 r            compitem = compmodelitemowner.GetItemById(EpfcModelItemType.EpfcITEM_AXIS, Convert.ToInt32(componentitemID))//通过id获取我所选择的圆柱的中心轴。
            Dim constrains As IpfcComponentConstraints
            Dim constrain As IpfcComponentConstraint
! f* }3 n: W) m! J. M0 j            constrains = New CpfcComponentConstraints
0 |) a4 @1 I9 x4 \- c5 L            Dim ids As Cintseq
4 L; Z: h" f# Z) }, R9 b. A! a2 y3 \            Dim path As IpfcComponentPath
7 y  e4 l; Y2 |6 D6 y7 k3 `            ids = New Cintseq
            path = (New CMpfcAssembly).CreateComponentPath(assembly, ids)//创建一个path
6 W* ]2 ?8 h! E9 i5 I3 [* A            Dim asmSelection As IpfcSelection
            Dim compSelection As IpfcSelection
: R& l) L# ~# I6 b) D/ C//通过modelitem创建selection对象，作为下面的reference
            asmSelection = (New CMpfcSelect).CreateModelItemSelection(asmitem, Nothing)
            compSelection = (New CMpfcSelect).CreateModelItemSelection(compitem, Nothing)
, y8 j9 C* w/ j7 j
            constrain = (New CCpfcComponentConstraint).Create(EpfcComponentConstraintType.EpfcASM_CONSTRAINT_ALIGN)
0 J+ Q4 V7 |: V            constrain.ComponentReference = asmSelection
- m& h* b' _6 q2 ?* C2 a; J! o            constrain.ComponentReference = compSelection
            'constrain.Offset = 10.0
            constrains.Insert(constrains.Count, constrain)
            assemblycompfeat.SetConstraints(constrains, path)//执行到这儿的时候发生异常
6 u* M6 h9 E, B+ r* m: c            assembly.Regenerate(Nothing)
6 X! `6 o! o' |" v  a请大侠过目指点

lzkeane

constrain.ComponentReference = asmSelection
$ D' @( M# N4 W6 U* D- @# ^4 b% F7 C  N$ v0 ]/ _2 |            constrain.ComponentReference = compSelection
) {# h4 _# `- b( u4 `% h这里错了