SolidWorks参数化建模VBA运行不成功？ 10

麻烦各位大佬看一下，这个程序能打开模型，能另存为模型，但是就是不能改变参数，不知道问题出在哪里，求教！

Dim swApp

Dim Part

On Error Resume Next

Set swapp = GetObject(, "SldWorks.Application")

If Err Then

Err.Clear

Set swApp = CreateObject("SldWorks.Application")

Set Part = swApp.ActiveDoc

swApp.Visible = true

swApp.UserControl = True

End If

Set objFSO = CreateObject("Scripting.FileSystemObject")

Set objFile = objFSO.GetFile("beam.SLDPRT")

Set Part = swApp.OpenDoc(objFSO.GetAbsolutePathName(objFile),1)

Set Part = swApp.ActivateDoc("beam.SLDPRT")

'swApp.Visible = true

Call ChangePara(Part, 0.3, 0.3)

Sub ChangePara(Part, Val1, Val2)

Part.Parameter("D1@草图2").System Value = Val1

Part.Parameter("D1@凸台-拉伸1").System Value = Val2

Part.EditRebuild

End Sub

Part.SaveAs(objFSO.GetParentFolderName(objFile) & "\" & "beam1.SLDPRT")

swApp.CloseDoc "beam.SLDPRT"