C# WPF What's wrong with this template? - wpf

Question

I'm trying to create a new window (child of MainWindow) that will display different numbers of rows with data each time. I used the following template that I copied from a wpf template tutorial. I've checked that the data are right and I can project them right with a MessageBox.Show window but I can't make them appear as bound properties. Here is the xaml...
<ListView x:Name="listUnits" x:FieldModifier="public" HorizontalAlignment="Left" Height="Auto" Margin="5,5,5,5" VerticalAlignment="Top" Width="Auto">
<ListView.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<TextBlock Text="Id:"/>
<TextBlock Text="{Binding pu_Id}" Width="Auto"/>
<TextBlock Text=" "/>
<TextBlock Text="{Binding pu_unitName}" Width="Auto"/>
</StackPanel>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
So although pu_unitName contains the data, they're are displayed in the new window.
The binding is done in the constructor:
public partial class ChooseUnit : Window
{
public ChooseUnit(List<XML_Handler.PrUnits> thisList)
{
InitializeComponent();
listUnits.ItemsSource = thisList;
}
}
The PrUnits is a class which contains variables including pu_id and pu_unitName. So what's wrong with this code?

Answer 1

Since you can only bind to public properties, you need to make sure that pu_Id and pu_UnitName are properties (and not fields) of the PrUnits class. Then your bindings will work.
Also note that this is not a binding:
listUnits.ItemsSource = thisList;
In general, you would set the DataContext of the parent window to an instance of a view model class and bind the ItemsSource property of the ListView to a property that returns the List<XML_Handler.PrUnits>:
<ListView x:Name="listUnits" ItemsSource="{Binding Units}">
...

Answer 2

In your .cs:
public partial class ChooseUnit : Window
{
public ChooseUnit(List<XML_Handler.PrUnits> thisList)
{
InitializeComponent();
this.DataContext = thisList;
}
}
What this does it assigns the data context of your window to the list of itemsa you are trying to pass. At this point every element in that window will have access to the passed in list.
And then in your XAML do this:
<ListView x:Name="listUnits" ItemsSource="{Binding .}" x:FieldModifier="public" HorizontalAlignment="Left" Height="Auto" Margin="5,5,5,5" VerticalAlignment="Top" Width="Auto">
This allows us to use binding as the entire window has access to the list. Hence ItemsSource="{Binding .}".
EDIT
Reading more into your question and thanks to Ash your class needs to expose Properties with INotifyPropertyChanged interface implemented.
This interface is expected by the WPF framework so it can subscribe to the changed events and update the UI.