VB.NET中的共享方法无法处理这个原因？

我有这个代码：

Public Shared Sub PopulateTextFields(ByRef stuffList As List(Of Stuff))
    Dim aStuff As New Stuff
    For Each aStuff In stuffList
        DoStuff(aStuff)
    Next
End Sub

Private Sub DoStuff(ByRef theStuff as Stuff)
    ....
End Sub

我得到以下错误突出显示DoStuff(aStuff)：

Cannot refer to an instance member of
a class from within a shared method or
shared member initializer without an
explicit instance of the class.

在编写Dim语句时,我没有得到Stuff的显式实例吗？

不明白什么是错的.提前致谢！