Imports ListBoxExtensions

My.Settings.ListBoxItems = Me.ListBox1.Items.ToStringCollection()

Public Module ListBoxExtensions
 
    ''' <summary>
    ''' Converts the specified a <see cref="ListBox.ObjectCollection"/> to a <see cref="StringCollection"/>.
    ''' </summary>
    ''' 
    ''' <param name="sender">
    ''' The source <see cref="ListBox.ObjectCollection"/>.
    ''' </param>
    ''' 
    ''' <returns>
    ''' The resulting <see cref="StringCollection"/>.
    ''' </returns>
    <Extension>
    <EditorBrowsable(EditorBrowsableState.Always)>
    <DebuggerStepThrough>
    Public Function ToStringCollection(ByVal sender As ListBox.ObjectCollection) As StringCollection
        Dim collection As New StringCollection()
 
        ' Intentionally, Will throw a InvalidCastException if the collection contains non-string types.
        For Each item As String In sender
            collection.Add(item)
        Next item
 
        Return collection
    End Function
 
End Module

If (My.Settings.ListBoxItems?.Count <> 0) Then
    ' Me.ListBox1.Items.Clear()
 
    Me.ListBox1.BeginUpdate()
    For Each item As String In My.Settings.ListBoxItems
        Me.ListBox1.Items.Add(item)
    Next item
    Me.ListBox1.EndUpdate()
End If