奇怪的行为：不使用Set而是将Variant Set设置为Object

Question

在将我的分析器从ProcessID写入VBA创建IE对象时，我遇到了这种奇怪的行为。请注意，即使win未将变量设置为IWebBrowser对象，也仍然Set是该IWebBrowser对象。

我想念什么吗？？？请问Matt，Continium，ThunderFrames ...有人喜欢Set me Straight吗？

Sub WierdBehavior()
    Dim win As Variant
    win = CreateObject("Shell.Application").Windows
    Debug.Print IsObject(win), TypeName(win)
End Sub

Answer 1

我可以通过让类返回接口作为其默认成员来复制行为。感谢John Coleman和Tim Williams给我这个主意。接口：IClass

VERSION 1.0 CLASS
BEGIN
  MultiUse = -1  'True
END
Attribute VB_Name = "IClass"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = False
Public Property Get getFoo() As Object
End Property

类别：Class2

VERSION 1.0 CLASS
BEGIN
  MultiUse = -1  'True
END
Attribute VB_Name = "Class2"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = False
Implements IClass
Private MyCollection As New Collection
Private Property Get IClass_getFoo() As Object
    Set Class1_getFoo = MyCollection
End Property

Public Function getInterface() As IClass
Attribute getInterface.VB_UserMemId = 0
    Set getInterface = Me
End Function

测试

Sub Test()
    Dim win As Variant
    Dim MyClass2 As New Class2
    win = MyClass2
    Debug.Print IsObject(win), TypeName(win)
End Sub

结果