Bind dymcly listBox after changes

The way to do this is to use something that automatically notifies attached ItemControls that it has updated when an item is added or removed. If only .NET provided a collection that was observed by something; gosh do you think that .NET could actually provided something like this; something like an ObservableCollection<ListProduct>. Google for ObservableCollection and WPF and you'll find shed loads of examples on how to do this.

Thanks for you help
I have this code
when I click on the button if the element exist on my list so I just modify the number if not I add it

when I add the elemnt myList is updated but when I click second time to modfy number it does not changes any explination please?
<pre>ObservableCollection<ListProduct> myList = new ObservableCollection<ListProduct>();
private void Button_Click(object sender, RoutedEventArgs e)
{
int index = myList.IndexOf((from par in myList
where par.name ="..."
select par).FirstOrDefault());
if(index != -1)
{
myList[index].number++;

}
else
{
myList.Add(new ListProduct { name = "...", number = 1 });
}
}

public class ListProduct{
public string productName { get; set;}
public double pricePerUnit { get; set;}
public int number {get; set;}
public double totalPrice {get; set;}
}</pre>
code Xaml
<ListView Name="ListView12" ItemsSource="{Binding}">
<ListView.View>
<GridView>
<GridViewColumn Header="name"
DisplayMemberBinding="{Binding name}">
<GridViewColumn Header="name"
DisplayMemberBinding="{Binding number}">
</GridView>
<ListView.View>
</ListView>

You shouldn't really add a question to your question. You could edit your question to add the extra info.

Anyway, the answer to your problem lies in the fact that you've confused a notification of a change to the collection with a notification of a change to a property. The problem that you are facing is that you need to change ListProduct so that it implements INotifyPropertyChanged like this:

public class ListProduct : INotifyPropertyChanged
{
  private string _productName;
  private double _pricePerUnit;
  private int _number;
  private double _totalPrice;

  public string ProductName
  {
    get { return _productName; }
    set {
      if (_productName != value)
      {
        _productName = value;
        OnChanged("ProductName");
      }
    }
  }

  // You get the idea about how to handle the other properties in here.
  public event PropertyChangedEventHandler PropertyChanged;
  private void OnChanged(string property)
  {
    PropertyChangedEventHandler handler = PropertyChanged;
    if (handler != null)
      handler(this, new PropertyChangedEventArgs(property));
  }
}

You didn't take too much time. Don't worry about it; we are here to help after all. :-D