2

我搜索了一下，但找不到足够相似的问题/答案。所以这里是：

我有一个名为 Project 的类对象。一个项目可以有多个与之相关的场景。

我为每个对象创建了类模块。但我相信，我在为给定项目实例化场景集合时遇到了困难。

以下是类模块：

1) 项目：

Private pProjectID As Integer 
Private pName As String 
Private pDateCreated As String 
Private pScenarios As cScenarios

' PROPERTIES

Public Property Get ProjectID() As Integer
    ProjectID = pProjectID 
End Property
Public Property Let ProjectID(value As Integer)
    pProjectID = value 
End Property
Public Property Get name() As String
    name = pName 
End Property 
Public Property Let name(value As String)
    pName = value 
End Property 
Public Property Get Scenarios() As cScenarios
    Set Scenarios = pScenarios 
End Property
Public Property Set Scenarios(value As cScenarios)
    Set pScenarios = value 
End Property

2）cScenarios集合类模块：

Private pScenarios As Collection

Private Sub Class_Initialize()
    Set pScenarios = New Collection
End Sub
Private Sub Class_Terminate()
    Set pScenarios = Nothing
End Sub
Public Function Item(index As Variant) As cScenario
    Set Item = pScenarios.Item(index)
End Function
Public Property Get Count() As Long
    Count = pScenarios.Count
End Property
Public Sub Add(obj As cScenario)
    pScenarios.Add obj
End Sub
Public Sub Remove(index As Variant)
    pScenarios.Remove index
End Sub

最后（3）场景类对象：

Private pScenarioID As Integer
Private pName As String
Private pDateCreated As String
Private pParent As cProject

Public Property Get ScenarioID() As Integer
    ScenarioID = pScenarioID
End Property
Public Property Let ScenarioID(value As Integer)
    pScenarioID = value
End Property
Public Property Get name() As String
    name = pName
End Property
Public Property Let name(value As String)
    pName = value
End Property
Public Property Get parent() As cProject
    parent = pParent
End Property
Public Property Let parent(value As cProject)
    pParent = value
End Property

这是一个标准模块：

Sub test1()

Dim cS As cScenarios
Dim s As cScenario

Set cS = New cScenarios

For i = 1 To 3
    Set s = New cScenario
    s.name = "s" & i
    cS.Add s
Next

Debug.Print cS.Item(3).name
Debug.Print cS.Count

End Sub

这行得通。一切都很好。目前。我能够用多种场景填充 cS。但是，如果我将场景集合作为项目的子对象引用（参见下面的 test2() ），我会在 cs.cs 上触发“运行时错误'91'：对象变量或未设置块变量”。添加通话。

Sub test2()

Dim p As cProject
Dim cS As cScenarios
Dim s As cScenario

Set p = New cProject
Set cS = p.Scenarios

For i = 1 To 3
    Set s = New cScenario
    s.name = "s" & i
    cS.Add s
Next

Debug.Print cS.Item(3).name
Debug.Print cS.Count

End Sub

我在构建班级模块时做错了什么和/或如何修复它？谢谢。

4

1 回答 1

1

pScenarios在尝试cProject使用Add(). 您可以通过向以下位置添加初始化程序来解决此问题cProject：

Private Sub Class_Initialize()
    Set pScenarios = New cScenarios
End Sub

这将保证cS实例不会Nothing在您尝试Add在其内部调用时出现test2。另一种方法（较弱的 IMO）是在内部p.Scenarios = new cScenarios更新后设置。另外，请确保属性设置器是而不是.ptest2cScenario.parentProperty SetProperty Let

于 2012-08-30T19:10:20.853 回答