Com 返回属性时未设置对象变量或with block变量时出错

我正在尝试在VB6应用程序中使用COM类。我做了一些包装纸。当我创建对象时，我看到消息

为Nothing 1

，因此它建议设置了成员变量且该变量不为null，但当我尝试使用属性返回此成员时，在返回行中我看到异常

对象变量或未设置块变量

。我不知道如何修理它

// MyComClass
This is a COM class with method Operation

// clsMyCom.cls
Private WithEvents m_myComClass As MyComClass

Private Sub Class_Initialize()
        
    If m_myComClass Is Nothing Then
        MsgBox "Is Nothing 1"
    End If
    
    Set m_myComClass = New MyComClass
    
    If m_myComClass Is Nothing Then
        MsgBox "Is Nothing 2"
    End If

End Sub

Public Property Get MyImplementation() As MyComClass

    If m_myComClass Is Nothing Then
        MsgBox "Is Nothing 3"
    End If
    
    // in this line I see exception:
    // object variable or with block variable not set
    MyImplementation = m_myComClass

End  Property

// usage
Dim variable As clsMyCom
Set variable = New clsMyCom
Call variable.MyImplementation.Operation(...)

---

将方法更改为：

Public Property Get MyImplementation() As MyComClass

    If m_myComClass Is Nothing Then
        MsgBox "Is Nothing 3"
    End If
    
    // in this line I see exception:
    // object variable or with block variable not set
    Set MyImplementation = m_myComClass

End  Property

---

为了清楚起见，您错过了

设置

将方法更改为：

Public Property Get MyImplementation() As MyComClass

    If m_myComClass Is Nothing Then
        MsgBox "Is Nothing 3"
    End If
    
    // in this line I see exception:
    // object variable or with block variable not set
    Set MyImplementation = m_myComClass

End  Property

---

需要说明的是，您错过了

集合
当返回对象时，我不知道
属性
中需要
集合
。
MyImplementation=
指定对象的默认属性（如果有），例如
MyImplementation.Text=“some string”
。错误“需要对象…”意味着
MyImplementation
在尝试分配给其默认属性时是
Nothing
。我不知道返回对象时
property
中需要
Set
。
MyImplementation=
分配给对象的默认属性（如果有），例如
MyImplementation.Text=“some string”
。错误“Object required…”表示
MyImplementation
在尝试分配给其默认属性时为
Nothing
。