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。
        Dim model As IpfcModel
5 G# m# O" w7 o, L4 x+ C+ e$ U, l: [* B) r        model = session.CurrentModel
        Dim assembly As IpfcAssembly
        assembly = CType(model, IpfcAssembly)
/ k$ }  ?9 l* G* w9 S
$ w& C! u' Y4 ]! O( L' V+ ?        MsgBox(CType(assembly, IpfcSolid).ListFeaturesByType(True, EpfcFeatureType.EpfcFEATTYPE_DATUM_AXIS).Count.ToString())
: @: U  G9 k5 v        'MsgBox(CType(assembly, IpfcModelItemOwner).ListItems(EpfcModelItemType.EpfcITEM_AXIS).Count.ToString())

        Dim models As IpfcModels
        models = session.ListModels()
+ p+ }  L, @* B8 g/ [9 T5 x/ i* L        Dim asmmodelitemowner As IpfcModelItemOwner
" n7 j  H/ j9 {' [4 N1 l8 i" W        asmmodelitemowner = CType(models(1), IpfcModelItemOwner)//获取到原先已经添加进来的圆柱作为modelitemowner

. a  v/ F9 h5 Y' F8 L; z) e        Dim compmodelitemowner As IpfcModelItemOwner
        compmodelitemowner = CType(componentModel, IpfcModelItemOwner)//后来添加的圆柱owner
        Dim asmitem As IpfcModelItem
        Dim compitem As IpfcModelItem
        Try
, p, i: Y9 v# k            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。
            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
# \1 R) U$ {% P& ]+ o& {            constrains = New CpfcComponentConstraints
" l5 Q: n( R* z2 X0 K3 n            Dim ids As Cintseq
            Dim path As IpfcComponentPath
' m5 A* s4 z$ q' S; `9 ^& L4 u$ R1 w            ids = New Cintseq
3 P- z; D! |6 a) k. w8 O            path = (New CMpfcAssembly).CreateComponentPath(assembly, ids)//创建一个path
            Dim asmSelection As IpfcSelection
            Dim compSelection As IpfcSelection
//通过modelitem创建selection对象，作为下面的reference
+ V& l. v. s( w6 b# r; Y$ n& G            asmSelection = (New CMpfcSelect).CreateModelItemSelection(asmitem, Nothing)
            compSelection = (New CMpfcSelect).CreateModelItemSelection(compitem, Nothing)

: f5 ^; u, i: u' e9 r" ?            constrain = (New CCpfcComponentConstraint).Create(EpfcComponentConstraintType.EpfcASM_CONSTRAINT_ALIGN)
* M( c) n  E# c0 f5 T) u" Q# t            constrain.ComponentReference = asmSelection
/ A* j. ^5 w2 Y4 U6 T! B            constrain.ComponentReference = compSelection
            'constrain.Offset = 10.0
            constrains.Insert(constrains.Count, constrain)
+ R/ e8 l) l7 V/ V            assemblycompfeat.SetConstraints(constrains, path)//执行到这儿的时候发生异常
) F+ l6 J% G, y" I. b6 f) z5 v            assembly.Regenerate(Nothing)
请大侠过目指点

lzkeane

constrain.ComponentReference = asmSelection
: W% p, B3 y) Q4 b% F7 C  N$ v0 ]/ _2 |            constrain.ComponentReference = compSelection
这里错了