Listview items not updating wpf vb.net - wpf

Question

I'm creating an application where we open a new window that has options to choose from in a listview, we extract one of the items in the listview and pass it on to another listview on a different window. I can populate the listview on the main window and can verify that the items are getting added during debug with an .items.count but they aren't getting added realtime. If I do a .show to open another instance of the window I see the items there but since I'm not planning on closing the main window out, how do you 'refresh' the listview to show the options that are clearly there?
I've read that if the listview is binded to a table, you can just re-bind the data to refresh it but since this listview isn't binded to anything and is just adding items to it with the .add function, I'm not sure how to 'refresh' it to show the values.
Edit:
Here is my code currently,
Public Class ObservableColl
Public Structure Steps
Private _Steps As List(Of String)
Property Steps() As List(Of String)
Get
Return _Steps
End Get
Set(ByVal value As List(Of String))
_Steps = value
End Set
End Property
End Structure
Dim songs As New ObservableCollection(Of Steps)
End Class
Private Sub CloseForm()
Dim stepArr As String() = Split(sCommon.presetSteps, ",")
Dim entries As New List(Of String)
For i = 0 To stepArr.Count - 1
entries.Add(stepArr(i))
Next
sCommon.form1.entries.Add(New Steps With {.Steps = entries}) 'Add list entries to the observableCollection
sCommon.form1.lvwCurrentSteps.DataContext = entries 'Assign the DataContext property to the observableCollection
If Not PresetList Is Nothing Then
Me.Close() 'Close this form and focus returns to the main window
End If
End Sub
<ListView Margin="49,23,0,33" HorizontalAlignment="Left" Width="230" Name="lvwCurrentSteps" SelectionMode="Multiple" ItemsSource="{Binding}" >
<ListView.ItemContainerStyle>
<Style TargetType="{x:Type ListViewItem}">
<Setter Property="BorderBrush" Value="LightGray" />
<Setter Property="BorderThickness" Value="0,0,0,1" />
</Style>
</ListView.ItemContainerStyle>
<ListView.View>
<GridView x:Name="myGridView">
<GridViewColumn Width="220" Header="Steps to run" DisplayMemberBinding="{Binding Path=Steps}">
</GridViewColumn>
</GridView>
</ListView.View>
</ListView>
I can validate that there are items in the listview with this method but the listview doesn't 'refresh' with these values when focus returns to the original window.
?sCommon.form1.lvwCurrentSteps.Items.Count
3

Answer 1

It's hard to tell from just this snippet but it looks like your logic is backwards in these two lines:
sCommon.form1.entries.Add(New Steps With {.Steps = entries}) 'Add list entries to the observableCollection
sCommon.form1.lvwCurrentSteps.DataContext = entries 'Assign the DataContext property to the observableCollection
I would expect that the DataContext you would want to use would be the collection you just added to, not the local variable that was what you added (which is a List Of String and so has no Steps property to support your DisplayMemberBinding). It also seems a little strange the way that the ObservableColl class is set up, with an ObservableCollection of objects containing a List.
I'm not sure what's happening with the count but you should validate that your basic logic is really doing what you mean it to.