使用Cleanup方法避免循环引用
DimobjClass2AsClass2
PrivateSubClass_Initialize()
  Debug.PrintTypeName(Me)&".Initialize"
SetobjClass2=NewClass2
  SetobjClass2.Class1=Me
  EndSub
PrivateSubClass_Terminate()
  SetobjClass2=Nothing
  Debug.PrintTypeName(Me)&".Terminate"
  EndSub
在Class2中添加如下的代码:
DimobjClass1AsClass1
PublicPropertySetClass1(ByRefNewValueAsClass1)
  SetobjClass1=NewValue
  EndProperty
PrivateSubClass_Initialize()
  Debug.PrintTypeName(Me)&".Initialize"
  EndSub
PrivateSubClass_Terminate()
  SetobjClass1=Nothing
  Debug.PrintTypeName(Me)&".Terminate"
  EndSub




