Persist collection at designtime

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C#

VB

.NET

collections

Hello,
Im creating a component that I call CustomerComponent, this component has only one property called Customers that receives a collection from my Customer class. Im trying to create a Form to edit this collection at design time through UITypeEditor. However, the values ​​added at design time do not reflect in the .Designer file, that is, the values ​​do not persist. Please help me make this work. Below my code and in the end my solution to download.

Here is the code for my CustomerComponent class:

Public Class CustomerComponent
    Inherits Component
    Public Property Customers As New Customers
End Class

Public Class Customer
    Public Property Name As String
    Public Property Age As Integer
End Class

<Editor(GetType(Customers.CustomersEditor), GetType(UITypeEditor))>
Public Class Customers

    Private List As New List(Of Customer)

    Public Function Add(ByVal Item As Customer) As Customer
        List.Add(Item)
        Return Item
    End Function

    Public Function Add(ByVal Name As String, ByVal Age As Integer) As Customer
        Dim Item As New Customer With {
            .Name = Name,
            .Age = Age
        }
        List.Add(Item)
        Return Item
    End Function

    Public Sub AddRange(ByVal Items() As Customer)
        Dim Item As Object
        For Each Item In Items
            List.Add(Item)
        Next
    End Sub

    Default Public ReadOnly Property Item(ByVal Index As Integer) As Customer
        Get
            Return CType(List(Index), Customer)
        End Get
    End Property

    Public Function Count() As Integer
        Return List.Count
    End Function

    Public Sub Clear()
        List.Clear()
    End Sub

    Public Overrides Function ToString() As String
        Return Nothing
    End Function

    Class CustomersEditor
        Inherits UITypeEditor
        Public Overrides Function GetEditStyle(ByVal context As ITypeDescriptorContext) As UITypeEditorEditStyle
            Return UITypeEditorEditStyle.Modal
        End Function

        Public Overrides Function EditValue(ByVal context As ITypeDescriptorContext, ByVal provider As System.IServiceProvider, ByVal value As Object) As Object
            Dim svc As IWindowsFormsEditorService = TryCast(provider.GetService(GetType(IWindowsFormsEditorService)), IWindowsFormsEditorService)
            Dim foo As Customers = TryCast(value, Customers)
            If svc IsNot Nothing AndAlso foo IsNot Nothing Then
                Using form As FormEditor = New FormEditor()
                    form.OtherFields = foo
                    If svc.ShowDialog(form) = DialogResult.OK Then
                        foo = form.OtherFields
                    End If
                End Using
            End If
            Return value
        End Function
    End Class
End Class

Here the form code used in UITypeEditor:

Public Class FormEditor
    Public Customers As New Customers
    Private Customer As Customer

    Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
        Customer = New Customer With {.Name = "Unknown Name"}
        PropertyGrid1.SelectedObject = Customer
        ListBox1.Items.Add(Cust.Name)
        Customers.Add(Customer)
    End Sub

    Private Sub FormEditor_Shown(sender As Object, e As EventArgs) Handles MyBase.Shown
        For i = 0 To Customers.Count - 1
            ListBox1.Items.Add(Customers(i).Name)
        Next i
    End Sub
End Class

Link to the solution
Download Solution[^]

What I have tried:

I tried to inherit the CollectionBase class in the Customers class, in which case the added values ​​are reflected in the .Designer file but with a syntax error.