ObservableCollection doesn't get bound to ListBox in codebehind - wpf

Question

I would like to bind a list box to an observable collection in code behind. This is what I am using for the binding:
Binding binding = new Binding();
binding.Source = symTable;
substanceList.SetBinding(ListBox.ItemsSourceProperty, binding);
symTable inherits from ObservableCollection, the Count property gets updated appropriatelly so I know I am adding elements correctly, but the list box isn't. I didn't know what to set the path to, since in XAML it is bound to the whole list.
Note: When adding individual items to the ListBox they get shown, so it is not a display issue. I also tried:
this.Resources.Add("symTable", symTable);
in the window constructor and then this:
but it says the resource cannot be resolved.
I also tried adding it as a resource in XAML but it didn't work again:
//in the window's resources.
<s:SymbolTable x:Key="symTable"/>
...
<ListBox x:Name="substanceList" ItemsSource="{Binding Source={StaticResource symTable}}"/>
and then in code behind:
symTable = (SymbolTable)this.FindResource("symTable");
Does anyone know any other way to do this in code behind or XAML, I think the ElementName refers to objects defined in code behind.
Here is part of the class definition for symTable:
public class SymbolTable : ObservableCollection<Substance>
{
Dictionary<string, Substance> symbolTable;
...
public Substance Insert(Substance s)
{
if (!symbolTable.ContainsKey(s.Name))
{
symbolTable.Add(s.Name, s);
Items.Add(s);
}
return symbolTable[s.Name];
}
Note alright so I just noticed the most weird thing, Items.Add wasn't raising the INotifyChanged event. I used Items.Add in my Insert method, I am guessing that Items.Add doesn't raise a INotifyChanged event so the ListBox wasn't getting updated, but when did Add instead of Items.Add then it worked. Do you know if this is indeed the case?

Answer 1

Ok, following the comments on your question, here is how to declare SymbolTable as resource in XAML and how to bind a ListBox to it. Note the XAML namespace declaration 'local', which refers to the local namespace/assembly, which is named ListBindingTest in my test project.
<Window x:Class="ListBindingTest.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:ListBindingTest"
Title="MainWindow" Height="350" Width="525">
<Window.Resources>
<local:SymbolTable x:Key="symTable"/>
</Window.Resources>
<Grid>
<ListBox ItemsSource="{Binding Source={StaticResource symTable}}"/>
</Grid>
</Window>
You may access the SymbolTable resource in code behind in your window class like this:
SymbolTable st = (SymbolTable)Resources["symTable"];
st.Add(new Substance());

Answer 2

The DisplayMemberPath needs to be a public property of symTable.

Answer 3

You could always just set the ItemSource directly on the listbox.
substanceList.ItemsSource = symTable;