Custom class methods in Excel - excel

I'm trying to create my own custom class module to handle custom class object.
Let's say i want to create a method witch would double the result of object property...
Class1:
Public Property Get MyObject() As Workbooks
Set MyObject = Application.Workbooks
End Property
When i create code like this:
Module1:
Function test()
Dim clstest As New Class1
Debug.Print "Result is: " & clstest.MyObject.Count
End Function
will give me
Result is: 1
since there is one worksheet in my object.
What i`m trying to achive is to make a custom function like this:
test.MyObject.DoubleResult '<- to make the result equals 2
I can`t get the idea how to pass the object to the new class function.
Class 2
Public Function DoubleResult() As Integer
DoubleResult = (The_Object_I_Created_earlier.Count) * 2
End Function
How i cant refer to the object "The_Object_I_Created_earlier"?

As far as I know you have to keep the count in an External variable.
You declare the public Long variable in a Module
Public ClassCount As Long
And on your class initialize and terminate you add and remove from it.
Private Sub Class_Initialize()
ClassCount = ClassCount + 1
End Sub
Private Sub Class_Terminate()
ClassCount = ClassCount - 1
End Sub

The design intent is not clear at all. But I can offer a simple primer with custom classes in VBA, and how one can contain the other.
Here is the code
MyClass1
Private m_value As Long
Private Sub Class_Initialize()
m_count = 0
End Sub
Public Sub InitializeWithCount(ByVal n As Long)
m_count = n
End Sub
Public Property Get Count() As Long
Count = m_count
End Property
MyClass2
Private m_obj As MyClass1
Private Sub Class_Initialize()
Set m_obj = New MyClass1
End Sub
Public Sub InitializeWithObject(ByVal x As MyClass1)
Set m_obj = x
End Sub
Public Sub InitializeWithValue(ByVal n As Long)
Set m_obj = New MyClass1
m_obj.InitializeWithCount n
End Sub
Public Property Get MyResult() As MyClass1
Set MyResult = m_obj
End Property
Module
for testing the above
Public Sub SO_Test()
Dim t1 As MyClass1
Dim t2 As MyClass2
Set t1 = New MyClass1 ' New Class1
t1.InitializeWithCount 100 ' Set value once to Long
Set t2 = New MyClass2 ' New Class2
t2.InitializeWithObject t1 ' Set value once to Class1
Debug.Print t2.MyResult.Count
' 100
t2.InitializeWithValue 200
Debug.Print t2.MyResult.Count
' 200
End Sub

Related

VBA - Trying to understand how to call Class Modules

I'm learning VBA through Google, YouTube, etc.. and I came across Class Modules.
I have a Tracker Template.
Every few days I get a report sent to me ("Ice cream FG Inv.xlsm")
While trying to understand Class Modules, I found a template that created a Class Module (within the Tracker Template) WBIceCreamFGINVxlsm creating a CodeName for all of the worksheets within the Ice Cream FG Inv.xlsm Workbook.
Example:
Public Property Get wsinventory() As Worksheet
Set wsinventory = Workbook.Worksheets("Inventory")
End Property
In my module, I want to reference wsinventory, but not understanding exactly how to 'call' the Class Module..
Both Workbooks are Open.
I tried to start with:
Dim Data As Variant
Data = wsinventory.Range("A1").CurrentRegion.Value (**Variable not Defined**)
Then I tried:
Dim wsinventory As Worksheets
With wsinventory
Dim Data As Variant
Data = .Range("A1").CurrentRegion.Value (**Object variable or With variable not set**)
End With
Do I still need to use:
Dim DataSource As Workbook
Set DataSource = Workbooks("Ice Cream FG Inv.xlsm")
With DataSource.Worksheets("Inventory")
End With
If so, what would be the reasoning for using Class Modules?
You need to create a class object before you can access the properties of that class.
Assuming you have this Class and naming it TestClass:
Private pwsinventory As Worksheet
Public Sub init()
Set pwsinventory = Worksheets("Inventory")
End Sub
Public Property Set wsinventory(lwsinventory As Worksheet)
Set pwsinventory = lwsinventory
End Property
Public Property Get wsinventory() As Worksheet
Set wsinventory = pwsinventory
End Property
You can set / get the properties like so:
Sub test()
Dim datacls As TestClass
Dim data As Worksheet
Set datacls = New TestClass
Set datacls.wsinventory = Worksheets("inventory")
Set data = datacls.wsinventory
Debug.Print data.Name
End Sub
This, however, is kind of weird and when you have a property you don't want to set (you need to pass an argument) you should use an initiate function. Unfortunately there is no way I know of to do this without manually calling that sub after the class object is created.
Sub Test2()
Dim datacls As TestClass
Set datacls = New TestClass
datacls.init
Debug.Print datacls.wsinventory.Name
End Sub
The most common case I use classes for is better containers. Generally storing many of the same class type inside an array / dictionary so it is clear what I'm calling, especially if I need to modify the data in the same manner for each instance.
I am going to give another example. Create a class definition and name it ArrayData, and define multiple initialization subroutines
ArrayData.cls
Private m_data() As Variant
Private Sub Class_Initialize()
End Sub
Public Sub IntializeEmpty(ByVal rows As Long, ByVal columns As Long)
ReDim m_data(1 To count, 1 To columns)
End Sub
Public Sub InitializeFromRange(ByRef target As Range)
If target.rows.count > 1 Or target.columns.count > 1 Then
m_data = target.Value2
Else
ReDim m_data(1 To 1, 1 To 1)
m_data(1, 1) = target.Value
End If
End Sub
Public Sub InitializeFromArray(ByRef data() As Variant)
m_data = data
End Sub
Public Property Get RowCount() As Long
RowCount = UBound(m_data, 1) - LBound(m_data, 1) + 1
End Property
Public Property Get ColCount() As Long
ColCount = UBound(m_data, 2) - LBound(m_data, 2) + 1
End Property
Public Property Get Item(ByVal row As Long, ByVal col As Long) As Variant
Item = m_data(row, col)
End Property
Public Property Let Item(ByVal row As Long, ByVal col As Long, ByVal x As Variant)
m_data(row, col) = x
End Property
Module
To test the code in a code module initialize the class with the New keyword and then call one of the custom initialization subroutines.
Public Sub TestArray()
Dim arr As New ArrayData
arr.InitializeFromRange Sheet1.Range("A2").Resize(10, 1)
Dim i As Long
For i = 1 To arr.RowCount
Debug.Print arr.Item(i, 1)
Next i
End Sub
PS. Also read this article on how to designate one property as the default. In the example above if Item was the default property then you could write code such as
Debug.Print arr(5,2)
instead of
Debug.Pring arr.Item(5,2)

Object doesn't support this property or method, If I declare variable with correct type

I declare 2 ClassModules:
Class1
Public MyProp As Class2
Public Sub MyMethod(val As Class2)
Set MyProp = val
MsgBox MyProp.Foo
End Sub
Class2
Public Foo As String
Sheet1
Private Sub CommandButton1_Click()
Dim a As Class1
Dim b As Class2
Set a = New Class1
Set b = New Class2
b.Foo = "Bar"
a.MyMethod (b)
End Sub
When I call a.MyMethod (b), I get "Object doesn't support this property or method"
but if I write the code as following, everything works as expected:
Private Sub CommandButton1_Click()
Dim a As Variant
Dim b As Variant
Set a = New Class1
Set b = New Class2
b.Foo = "Bar"
a.MyMethod (b)
End Sub
What Am I doing wrong?

How do you use a public variable in a Class Module?

I'm using a Class Module to make a collection of save buttons all do the same thing. But when I try to get them to run a sub that requires a variable I can't get the variable passed to them.
Edited using #Teasel's advice about properties. The problem seems to be the Let Property is not allowing me to set the variable from Module1.
Class1
Public WithEvents SaveBtn As MSForms.CommandButton
Dim currentrow As Long
Private Sub SaveBtn_Click()
SendMessage
`Even if I just have it Msgbox currentrow it returns 0
End Sub
Property Let GetRow(myrow As Long)
currentrow = myrow
End Property
Property Get GetRow() As Long
GetRow = currentrow
End Property
Module1
`Trying to send the value into the Class using Let
Private Sub SendRow_Click()
Module1.GetRow = 22
End Sub
`Trying to Get the value back from the Class
Public Sub SendMessage()
Dim therow As Long
therow = Module1.GetRow
`I get the "Method or Data Member not found" error in the line above
MsgBox therow
End Sub
UserForm1
`This part works fine
Dim colSaveButtons As New Collection
Private Sub UserForm_Initialize()
Dim i As Long
Dim ctl As MSForms.Control
Dim obEvents As Class1
For Each ctl In Me.Controls
If TypeOf ctl Is MSForms.CommandButton Then
For i = 0 To 5
If ctl.Name = "btnSavePage" & i Then
Set obEvents = New Class1
Set obEvents.SaveBtn = ctl
colSaveButtons.Add obEvents
End If
Next
End If
Next ctl
End Sub
Add a "CurrentRow" field to your class module:
Public WithEvents SaveBtn As MSForms.CommandButton
Public CurrentRow As Long '<< add this
Private Sub SaveBtn_Click()
SendMessage CurrentRow
End Sub
In your loop:
...
If ctl.Name = "btnSavePage" & i Then
Set obEvents = New Class1
obEvents.CurrentRow = 10 'or whatever...
Set obEvents.SaveBtn = ctl
colSaveButtons.Add obEvents
End If
...
And your SendMessage method:
Public Sub SendMessage(CurrentRow As Long)
MsgBox "This works"
End Sub
You can use two differents ways to achieve that.
1. Public Property
To simple access your variable's value you need a Get property and to set its value you need a Let property.
In your Module:
'Your module private variable
Dim nameOfYourModuleVariable As String
...
'Set property to assign a value to your variable
Public Property Let nameOfYourProperty(value As String)
nameOfYourModuleVariable = value
End Property
'Get property to return the value of your variable
Public Property Get nameOfYourProperty() As String
nameOfYourProperty = nameOfYourModuleVariable
End Property
You can then use it like this:
'Set the value
MyModule.nameOfYourProperty = "foo"
'Get the value
MyModule.nameOfYourProperty
I highly recommend to use properties to do such things however you can also simply set your variable as public as shown in point 2.
2. Public Variable
Define your variable to be public so you can access it from everywhere.
In your Module:
Public nameOfYourVariable As String
Get or set the value from another module:
'Set the value
MyModule.nameOfYourVariable = "foo"
'Get the value
MyModule.nameOfYourVariable

Excel VBA: Is there a way to reference an instance of a class stored in a dictionary?

I currently have instances of classes stored using the data structure presented in the image below. Each -List item is a dictionary and each -Info item is an instance of a class.
I read elsewhere that if you Set an instance variable equal to another instance, it just references the original instance. Is this correct?
I have been able to create a reference for fileInfo(1) (in the image) using the following code.
Dim prflInfo As File_Info
Set prflInfo = New File_Info
Set prflInfo = fileList.Items(0)
I have attempted to reference the branchInfo instance using the following code, but I get a Run-time error 13: Type mismatch when I attempt to do so.
Dim prbrInfo As Branch_Info
With prflInfo
Set prbrInfo = New Branch_Info
brKey = .getbrKey(0)
Set prbrInfo = .getbrItem(brKey)
End With
Edit: Included below is the code for the File_Info class. All other classes follow this basic model.
'Class Module: File_Info
'Initialise class variables
Private pfileID As Integer
Private pfilePath As String
Private pfileName As String
Private pbranchList As Scripting.Dictionary
'Declare variantcopy subroutine
Private Declare Sub VariantCopy Lib "OleAut32" (pvarDest As Any, pvargSrc As Any)
Private Sub Class_Initialize()
Set pbranchList = New Scripting.Dictionary
End Sub
Public Property Let fileID(pfileIDi As Variant)
pfileID = pfileIDi
End Property
Public Property Get fileID() As Variant
fileID = pfileID
End Property
Public Property Let filePath(pfilePathi As Variant)
pfilePath = pfilePathi
End Property
Public Property Get filePath() As Variant
filePath = pfilePath
End Property
Public Property Let fileName(pfileNamei As Variant)
pfileName = pfileNamei
End Property
Public Property Get fileName() As Variant
fileName = pfileName
End Property
Public Sub addbrConn(branch As Branch_Info)
pbranchList.Add branch.branchID, branch.brConn
Debug.Print "addbrConn ID: " & branch.branchID
End Sub
Public Sub addBranch(branch As Branch_Info)
pbranchList.Add branch.branchID, branch
Debug.Print pbranchList.Count
End Sub
Public Function countbrList()
countbrList = pbranchList.Count
End Function
Public Function getbrKey(Key As Variant)
getbrKey = pbranchList.Keys(Key)
End Function
Public Function getbrItem(Key As Variant)
getbrItem = GetByRefVariant(pbranchList.Items(Key))
End Function
Public Sub dpbrList()
With pbranchList
Debug.Print pbranchList.Count
For k = 1 To pbranchList.Count
Debug.Print .Keys(k - 1), .Items(k - 1)
Next k
End With
End Sub
Public Sub updbrList(branch As Branch_Info)
Dim branchID As String
branchID = branch.branchID
If pbranchList.exists(branchID) Then
pbranchList.Remove (branchID)
pbranchList.Add branchID, branch
Debug.Print "Complete: " & branchID & " added."
Else
Debug.Print "Error: " & branchID & "does not exist."
End If
End Sub
Private Function GetByRefVariant(ByRef var As Variant) As Variant
VariantCopy GetByRefVariant, var
End Function
Is there a way to reference the branchInfo class, to make it easier to extract the data within it?
Thanks!
Eeshwar
I do things differently in that I iterate through the keys list using a For ... each loop rather than referring to an item number. Here is a snippet that works using two levels.
You can ignore the lines where the property values are written to an array, but they were part of the original code.
cf.Dependents is a dictionary of cDependents within the cFamily object
'Declarations in Main Module
Dim dF As Dictionary, cF As cFamily, cD As cDependents
Dim I As Long, J As Long
Dim V As Variant, W As Variant
...
For Each V In dF
I = I + 1
Set cF = dF(V)
With cF
vRes(I, 1) = .FirstName
vRes(I, 2) = .LastName
vRes(I, 3) = .Birthdate
J = 2
For Each W In .Dependents
J = J + 2
Set cD = .Dependents(W)
With cD
vRes(I, J) = .Relation
vRes(I, J + 1) = .DepName
End With
Next W
End With
Next V
Note that in the sequence, as you show in your question:
set Obj = new Obj
set Obj = myClass(0)
the first line is unnecessary.
IMO it is possible to use simple VBA.Collection, here example for the FileList and BranchList. In this example List classes have Items and Info classes have reference to List where List is wrapper for a VBA.Collection. HTH
For more reading have a look e.g. here.
FileList Class
Option Explicit
Private m_fileInfoCollection As FileInfoCollection
Private Sub Class_Initialize()
Set m_fileInfoCollection = New FileInfoCollection
End Sub
Public Property Get Items() As FileInfoCollection
Set Items = m_fileInfoCollection
End Property
FileInfo Class
Option Explicit
Private m_branchList As BranchList
Private m_fileID As Integer
Private Sub Class_Initialize()
Set m_branchList = New BranchList
End Sub
Public Property Get FileID() As Integer
FileID = m_fileID
End Property
Public Property Let FileID(ByVal vNewValue As Integer)
m_fileID = vNewValue
End Property
Public Property Get BranchList() As BranchList
Set BranchList = m_branchList
End Property
FileInfoCollection Class
Option Explicit
Private m_collection As VBA.Collection
Private Sub Class_Initialize()
Set m_collection = New VBA.Collection
End Sub
Public Sub Add(ByVal newItem As FileInfo)
m_collection.Add newItem, CStr(newItem.FileID)
End Sub
Public Function ItemByKey(ByVal key As String) As FileInfo
Set ItemByKey = m_collection(key)
End Function
Public Function ItemByIndex(ByVal index As Long) As FileInfo
Set ItemByIndex = m_collection(index)
End Function
Public Function Count() As Long
Count = m_collection.Count
End Function
BranchList Class
Option Explicit
Private m_branchInfoCollection As BranchInfoCollection
Private Sub Class_Initialize()
Set m_branchInfoCollection = New BranchInfoCollection
End Sub
Public Property Get Items() As BranchInfoCollection
Set Items = m_branchInfoCollection
End Property
BranchInfo Class
Option Explicit
Private m_branchID As Integer
Public Property Get branchID() As Integer
branchID = m_branchID
End Property
Public Property Let branchID(ByVal vNewValue As Integer)
m_branchID = vNewValue
End Property
BranchInfoCollection Class
Option Explicit
Private m_collection As VBA.Collection
Private Sub Class_Initialize()
Set m_collection = New VBA.Collection
End Sub
Public Sub Add(ByVal newItem As BranchInfo)
m_collection.Add newItem, CStr(newItem.branchID)
End Sub
Public Function ItemByKey(ByVal key As String) As BranchInfo
Set ItemByKey = m_collection(key)
End Function
Public Function ItemByIndex(ByVal index As Long) As BranchInfo
Set ItemByIndex = m_collection(index)
End Function
Public Function Count() As Long
Count = m_collection.Count
End Function
Standard Module
Option Explicit
Sub Demo()
' Fill
Dim bi As BranchInfo
Set bi = New BranchInfo
bi.branchID = 111
Dim fi As FileInfo
Set fi = New FileInfo
fi.FileID = 222
fi.BranchList.Items.Add bi
Dim fl As FileList
Set fl = New FileList
fl.Items.Add fi
' Get
Dim fi1 As FileInfo
Set fi1 = fl.Items.ItemByIndex(1)
Dim bi1 As BranchInfo
Set bi1 = fi1.BranchList.Items(1)
End Sub

Is it possible to access a parent property from a child that is in a collection?

I've researched as much as I can and never found a definitive answer on this for VBA.
This older StackOverflow post has almost everything, but not quite. VBA Classes - How to have a class hold additional classes
Bottom line - I have a class CClock, which is parent to a Collection of CContacts, which is parent to a CContact.
Is there any way to get at a property of the CClock class from a CContact. So something like Debug.Print , clsContact.Parent.Parent.Lawyer in the code below?
I've tried setting the parents as I thought they should be but get the below error almost immediately at Set clsClock = New CClock. When I follow the code it goes to class terminate event in the Contacts collection, which I can't figure out. (Although that is probably why the error below comes up.)
91 - Object Variable or With Variable not set
The various classes and a quick test rig are below (all based on Dick Kusleika's post in the link.) Thanks.
(Edit- added the test routine, whooopsy)
Sub test()
Dim i As Long, j As Long
Dim clsClocks As CClocks
Dim clsClock As CClock
Dim clsContact As CContact
Set clsClocks = New CClocks
For i = 1 To 3
Set clsClock = New CClock
clsClock.Lawyer = "lawyer " & i
For j = 1 To 3
Set clsContact = New CContact
clsContact.ContactName = "Business Contact " & i & "-" & j
clsClock.Contacts.Add clsContact
Next j
clsClocks.Add clsClock
Next i
For i = 1 To 2
Set clsContact = New CContact
clsContact.ContactName = "Business Contact 66" & "-" & i
clsClocks(2).Contacts.Add clsContact
Next i
'write the data backout again
For Each clsClock In clsClocks
Debug.Print clsClock.Lawyer
For Each clsContact In clsClock.Contacts
Debug.Print , clsContact.ContactName
Debug.Print , clsContact.Parent.Parent.Lawyer
Next clsContact
Next clsClock
End Sub
Clas CClocks
'CClocks
Option Explicit
Private mcolClocks As Collection
Private Sub Class_Initialize()
Set mcolClocks = New Collection
End Sub
Private Sub Class_Terminate()
Set mcolClocks = Nothing
End Sub
Public Property Get NewEnum() As IUnknown
Set NewEnum = mcolClocks.[_NewEnum]
End Property
Public Sub Add(clsClock As CClock)
If clsClock.ClockID = 0 Then
clsClock.ClockID = Me.Count + 1
End If
Set clsClock.Parent = Me
mcolClocks.Add clsClock, CStr(clsClock.ClockID)
End Sub
Public Property Get Clock(vItem As Variant) As CClock
Set Clock = mcolClocks.Item(vItem)
End Property
Public Property Get Count() As Long
Count = mcolClocks.Count
End Property
Public Sub Remove(vItem As Variant)
clsClock.Remove vItem
End Sub
Public Sub Clear()
Set clsClock = New Collection
End Sub
Class CClock
'CClock
Private mlClockID As Long
Private msLawyer As String
Private mlParentPtr As Long
Private mclsContacts As CContacts
Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" _
(dest As Any, Source As Any, ByVal bytes As Long)
Public Property Set Contacts(ByVal clsContacts As CContacts): Set mclsContacts = clsContacts: End Property
Public Property Get Contacts() As CContacts: Set Contacts = mclsContacts: End Property
Public Property Let ClockID(ByVal lClockID As Long): mlClockID = lClockID: End Property
Public Property Get ClockID() As Long: ClockID = mlClockID: End Property
Public Property Let Lawyer(ByVal sLawyer As String): msLawyer = sLawyer: End Property
Public Property Get Lawyer() As String: Lawyer = msLawyer: End Property
Public Property Get Parent() As CClocks: Set Parent = ObjFromPtr(mlParentPtr): End Property
Public Property Set Parent(obj As CClocks): mlParentPtr = ObjPtr(obj): End Property
Private Function ObjFromPtr(ByVal pObj As Long) As Object
Dim obj As Object
CopyMemory obj, pObj, 4
Set ObjFromPtr = obj
' manually destroy the temporary object variable
' (if you omit this step you'll get a GPF!)
CopyMemory obj, 0&, 4
End Function
Private Sub Class_Initialize()
Set mclsContacts = New CContacts
Set Me.Contacts.Parent = Me
End Sub
Private Sub Class_Terminate()
Set mclsContacts = Nothing
End Sub
'CContacts
Option Explicit
Private mcolContacts As Collection
Private mlParentPtr As Long
Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" _
(dest As Any, Source As Any, ByVal bytes As Long)
Public Property Get Parent() As CClock: Set Parent = ObjFromPtr(mlParentPtr): End Property
Private Sub Class_Initialize()
Set mcolContacts = New Collection
End Sub
Private Sub Class_Terminate()
Set mcolContacts = Nothing
End Sub
Public Property Get NewEnum() As IUnknown
Set NewEnum = mcolContacts.[_NewEnum]
End Property
Public Sub Add(clsContact As CContact)
If clsContact.ContactID = 0 Then
clsContact.ContactID = Me.Count + 1
End If
Set clsContact.Parent = Me
mcolContacts.Add clsContact, CStr(clsContact.ContactID)
End Sub
Public Property Get Clock(vItem As Variant) As CContact
Set Clock = mcolContacts.Item(vItem)
End Property
Public Property Get Count() As Long
Count = mcolContacts.Count
End Property
Public Sub Remove(vItem As Variant)
clsContact.Remove vItem
End Sub
Public Sub Clear()
Set clsContact = New Colletion
End Sub
Private Function ObjFromPtr(ByVal pObj As Long) As Object
Dim obj As Object
CopyMemory obj, pObj, 4
Set ObjFromPtr = obj
' manually destroy the temporary object variable
' (if you omit this step you'll get a GPF!)
CopyMemory obj, 0&, 4
End Function
Class CContact
'CContact
Private mlContactID As Long
Private msContactName As String
Private mlParentPtr As Long
Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" _
(dest As Any, Source As Any, ByVal bytes As Long)
Public Property Let ContactID(ByVal lContactID As Long): mlContactID = lContactID: End Property
Public Property Get ContactID() As Long: ContactID = mlContactID: End Property
Public Property Let ContactName(ByVal sContactName As String): msContactName = sContactName: End Property
Public Property Get ContactName() As String: ContactName = msContactName: End Property
Public Property Get Parent() As CContacts: Set Parent = ObjFromPtr(mlParentPtr): End Property
Public Property Set Parent(obj As CContacts): mlParentPtr = ObjPtr(obj): End Property
Private Function ObjFromPtr(ByVal pObj As Long) As Object
Dim obj As Object
CopyMemory obj, pObj, 4
Set ObjFromPtr = obj
' manually destroy the temporary object variable
' (if you omit this step you'll get a GPF!)
CopyMemory obj, 0&, 4
End Function
If you figure out how to access the kernel memory to do this, let me know. Take a look at the source code of vbWatchDog for some hints. I have been studying it to try to gain access to the call stack. I haven't figured it out yet.
I'll show you how to fake it though. I'm going to simplify this a bit. You'll need to apply the principle to your own code. The trick is kind of ugly. It requires that we call an Initialize routine each time we create a new child object
The Parent Class:
'Class Parent
Option Explicit
Private mName as String
Public Property Get Name() as String
Name = mName()
End Property
Public Property Let Name(value As String)
mName = value
End Property
The Child class
'Class Child
Option Explicit
Private mParent as Parent
Public Property Get Parent() as Parent
Set Parent = mParent
End Property
Public Property Let Name(Obj as Parent)
Set mParent = Obj
End Property
Public Sub Initialize(Obj as Parent)
Set Me.Parent = Obj
End Sub
Creating a Child object:
Sub CreateChild()
Dim parentObject As New Parent
' create child object with parent property
Dim childObject As New Child
childObject.Initialize(parentObject)
End Sub

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