class - 在 VBA 中使用自定义数据类型

Question

我正在尝试在 VBA for Excel 中创建自定义数据类型。我们称这种数据类型为“卡车”。每辆卡车都有以下属性：

NumberOfAxles (this is an integer)
AxleWeights (this is an array of doubles)
AxleSpacings (this is an array of doubles)

我可以创建许多数据类型“卡车”（卡车（1）、卡车（2）...等）的实例，并将上面列出的属性读/写到该实例吗？

例子：

Truck(1).NumberOfAxles = 2
Truck(1).AxleWeights(1) = 15.0
Truck(1).AxleWeights(2) = 30.0
Truck(1).AxleSpacings(1) = 8.0

Truck(2).NumberOfAxles = 3
Truck(2).AxleWeights(1) = 8.0
Truck(2).AxleWeights(2) = 10.0
Truck(2).AxleWeights(3) = 12.0
Truck(2).AxleSpacings(1) = 20.0
Truck(2).AxleSpacings(2) = 4.0

等等。上面的语法很可能是错误的，我只是想展示我需要提出的结构。

我正在尝试将数据写入数据结构并根据需要调用它，例如

Truck(i).NumberOfAxles
Truck(i).AxleWeights(j)
Truck(i).AxleSpacings(j)

非常感谢你！

Answer 1

你当然可以：

Option Explicit

'***** User defined type
Public Type MyType
     MyInt As Integer
     MyString As String
     MyDoubleArr(2) As Double
End Type

'***** Testing MyType as single variable
Public Sub MyFirstSub()
    Dim MyVar As MyType

    MyVar.MyInt = 2
    MyVar.MyString = "cool"
    MyVar.MyDoubleArr(0) = 1
    MyVar.MyDoubleArr(1) = 2
    MyVar.MyDoubleArr(2) = 3

    Debug.Print "MyVar: " & MyVar.MyInt & " " & MyVar.MyString & " " & MyVar.MyDoubleArr(0) & " " & MyVar.MyDoubleArr(1) & " " & MyVar.MyDoubleArr(2)
End Sub

'***** Testing MyType as an array
Public Sub MySecondSub()
    Dim MyArr(2) As MyType
    Dim i As Integer

    MyArr(0).MyInt = 31
    MyArr(0).MyString = "VBA"
    MyArr(0).MyDoubleArr(0) = 1
    MyArr(0).MyDoubleArr(1) = 2
    MyArr(0).MyDoubleArr(2) = 3
    MyArr(1).MyInt = 32
    MyArr(1).MyString = "is"
    MyArr(1).MyDoubleArr(0) = 11
    MyArr(1).MyDoubleArr(1) = 22
    MyArr(1).MyDoubleArr(2) = 33
    MyArr(2).MyInt = 33
    MyArr(2).MyString = "cool"
    MyArr(2).MyDoubleArr(0) = 111
    MyArr(2).MyDoubleArr(1) = 222
    MyArr(2).MyDoubleArr(2) = 333

    For i = LBound(MyArr) To UBound(MyArr)
        Debug.Print "MyArr: " & MyArr(i).MyString & " " & MyArr(i).MyInt & " " & MyArr(i).MyDoubleArr(0) & " " & MyArr(i).MyDoubleArr(1) & " " & MyArr(i).MyDoubleArr(2)
    Next
End Sub

Answer 2

看起来您想将 Truck 定义为Class具有 NumberOfAxles、AxleWeights 和 AxleSpacings 属性的卡车。

这可以在CLASS MODULE中定义（这里命名为clsTrucks）

Option Explicit

Private tID As String
Private tNumberOfAxles As Double
Private tAxleSpacings As Double


Public Property Get truckID() As String
    truckID = tID
End Property

Public Property Let truckID(value As String)
    tID = value
End Property

Public Property Get truckNumberOfAxles() As Double
    truckNumberOfAxles = tNumberOfAxles
End Property

Public Property Let truckNumberOfAxles(value As Double)
    tNumberOfAxles = value
End Property

Public Property Get truckAxleSpacings() As Double
    truckAxleSpacings = tAxleSpacings
End Property

Public Property Let truckAxleSpacings(value As Double)
    tAxleSpacings = value
End Property

然后在MODULE中，以下定义了一辆新卡车及其属性，并将其添加到卡车集合中，然后检索该集合。

Option Explicit

Public TruckCollection As New Collection

Sub DefineNewTruck()
Dim tempTruck As clsTrucks
Dim i As Long

    'Add 5 trucks
    For i = 1 To 5
        Set tempTruck = New clsTrucks
        'Random data
        tempTruck.truckID = "Truck" & i
        tempTruck.truckAxleSpacings = 13.5 + i
        tempTruck.truckNumberOfAxles = 20.5 + i

        'tempTruck.truckID is the collection key
        TruckCollection.Add tempTruck, tempTruck.truckID
    Next i

    'retrieve 5 trucks
    For i = 1 To 5
        'retrieve by collection index
        Debug.Print TruckCollection(i).truckAxleSpacings
        'retrieve by key
        Debug.Print TruckCollection("Truck" & i).truckAxleSpacings

    Next i

End Sub

有几种方法可以做到这一点，因此它实际上取决于您打算如何使用数据来确定类/集合是最佳设置还是数组/字典等。