My custom collection isn't working

[Winston]

Hey guys, i'm extending the standard listbox control, and im intending to add a collections property, ok so far so good property added, and i've made a new class that derives from collectionbase, and i've implemented the appropriate methods etc, but the problem here is, in the form designer, i add items inside the collection editor form, and thats fine, etc, but as soon as i close the form or anything and open it back up, and go back in the collections property the added items isnt there, ive been monitoring the InitializeComponent call and i notice that there isn't any code being generated when i add an item in the form designer, what have i missed out?

 

Thanks guys.

[PlausiblyDamp]

have you looked at either of the following?

http://www.xtremedotnettalk.com/showthread.php?t=70318

http://www.xtremedotnettalk.com/showthread.php?t=70320

They should give you a good idea of what is required, if they don't help could you post some of the code you are using?

[Winston]

Yeah i've read the article on divil's site.

 

Here's the code

 

    <Description("Contains Enhanced Listbox items."), _
   EditorAttribute(GetType(System.ComponentModel.Design.CollectionEditor), GetType(System.Drawing.Design.UITypeEditor)), _
DesignerSerializationVisibility(DesignerSerializationVisibility.Content)> _
   Public Property ListItems() As ListBoxItemCollection
       Get
           Return Me.listItemCollection
       End Get
       Set(ByVal Value As ListBoxItemCollection)
           Me.listItemCollection = Value
       End Set
   End Property

 

that's the property i have for a class that inherits from ListBox, and listItemCollection is an instance variable inside the class that derives from ListBox.

 

 

<Serializable()> _
Public Class ListBoxItemCollection : Inherits CollectionBase
   Public Sub New()
       MyBase.New()
   End Sub

   Public Sub New(ByVal value As ListBoxItemCollection)
       MyBase.New()
       Me.AddRange(value)
   End Sub

   Public Sub New(ByVal value() As ListBoxItem)
       MyBase.New()
       Me.AddRange(value)
   End Sub

   Default Public Property Item(ByVal index As Integer) As ListBoxItem
       Get
           Return CType(List(index), ListBoxItem)
       End Get
       Set(ByVal Value As ListBoxItem)
           List(index) = Value
       End Set
   End Property

   Public Function Add(ByVal value As ListBoxItem) As Integer
       Return List.Add(value)
       MessageBox.Show("hey")
   End Function

   Public Overloads Sub AddRange(ByVal value() As ListBoxItem)
       Dim i As Integer = 0
       Do While (i < value.Length)
           Me.Add(value(i))
           i = (i + 1)
       Loop
       MessageBox.Show("hey")
   End Sub

   Public Overloads Sub AddRange(ByVal value As ListBoxItemCollection)
       Dim i As Integer = 0
       Do While (i < value.Count)
           Me.Add(value(i))
           i = (i + 1)
       Loop
       MessageBox.Show("hey")
   End Sub

   Public Function IndexOf(ByVal value As ListBoxItem) As Integer
       Return List.IndexOf(value)
   End Function
   Public Sub CopyTo(ByVal array() As ListBoxItem, ByVal index As Integer)
       List.CopyTo(array, index)
   End Sub

   Public Sub Insert(ByVal index As Integer, ByVal value As ListBoxItem)
       List.Insert(index, value)
   End Sub


   Public Sub Remove(ByVal value As ListBoxItem)
       List.Remove(value)
   End Sub


   Public Function Contains(ByVal value As ListBoxItem) As Boolean
       Return List.Contains(value)
   End Function

End Class

 

That's the class that derives from CollectionBase

 

and i have another classe called ListBoxItem, which just has 3 Properties inside nothing else.

[AlexCode]

Did you tryed to change the DesignerSerializationVisibility(DesignerSerializationVisibility.Content) to DesignerSerializationVisibility(DesignerSerializationVisibility.Visible) ?

[Winston]

Well i've figured it out, thanks for the help guys, the main problem was, i was using a custom item type, and basicaly i need to create a custom TypeConverter for my item type, so i have to look into that. Like my main problem was when the items were added through the Collection Editor dialog, i doesn't know how to generate code for the items.