如何修改衍生零件

今天碰到一个客户问题，他想修改衍生零件的属性：UseColorOverridesFromSource, 该布尔值用来决定是否使用衍生源零件中的体，特征和面的颜色。他的代码是这样写的：

    Public Sub ModifyDerivedPartExample()

         Dim oDoc As PartDocument

        oDoc = _InvApplication.ActiveDocumen

         Dim oCompDef As PartComponentDefinition

        oCompDef = oDoc.ComponentDefinition

         Dim oDerivedPartComps As DerivedPartComponents

        oDerivedPartComps =oCompDef.ReferenceComponents.DerivedPartComponents

         Dim oDerivePart As DerivedPartComponent

        oDerivePart = oDerivedPartComps.Item(1)

        oDerivePart.Definition.IncludeAll()

       oDerivePart.Definition.UseColorOverridesFromSource = True

        oDoc.Rebuild()

     End Sub

编译和运行都 没有任何错误，但结果是衍生件的颜色并没有使用源零件的颜色。这是为何？
其实，这里有个小小的技巧。当需要修改衍生零件属性时，需要先创建一个临时的衍生定义DerivedPartDefinition。把该定义的属性按照希望的内容设定好，再覆盖衍生件的定义。

    Public Sub ModifyDerivedPartExample() 

        DimoDoc As PartDocument

        oDoc = _InvApplication.ActiveDocument 

        DimoCompDef As PartComponentDefinition

        oCompDef = oDoc.ComponentDefinition 

        DimoDerivedPartComps As DerivedPartComponents

        oDerivedPartComps =oCompDef.ReferenceComponents.DerivedPartComponents 

        DimoDerivePart As DerivedPartComponent

        oDerivePart = oDerivedPartComps.Item(1) 

        '定义一个临时的 DerivedPartDefinition变量

        '用旧的定义初始化。即复制一份

        DimoDerivedPartDef As DerivedPartDefinition

        oDerivedPartDef =oDerivePart.Definition 

        '对这个临时变量做你需要的修改

       oDerivedPartDef.UseColorOverridesFromSource = True 

        ' 覆盖衍生件旧的定义

        oDerivePart.Definition = oDerivedPartDef 

    End Sub