Binding List to DataGrid Silverlight

Question

Hi,

I have a problem binding List to a DataGrid element. I've created a class that implements INotifyPropertyChange and keeps list of orders:

public class Order : INotifyPropertyChanged
{

    private String customerName;

    public String CustomerName
    {
        get { return customerName; }
        set { 
                customerName = value;
                NotifyPropertyChanged("CustomerName");
            }
    }

    private List<String> orderList = new List<string>();

    public List<String> OrderList
    {
        get { return orderList; }
        set { 
                orderList = value;
                NotifyPropertyChanged("OrderList");
            }
    } 




    public void NotifyPropertyChanged(string propertyName)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
    }  

In xaml a have a simple DataGrid component that Binds the OrderList element:

<data:DataGrid x:Name="OrderList" ItemsSource="{**Binding OrderList**, Mode=TwoWay}" Height="500" Width="250" Margin="0,0,0,0" VerticalAlignment="Center" 

I also have a button in GUI taht adds a element to OrderList:

order.OrderList.Add("item");

The DataContext is set to the global object:

      Order order = new Order();
      OrderList.DataContext = order;

The problem is that when i Click the button, the item does not apear in dataGrid. It apears after a click on a grid row. It seams like INotifyPropertyChange does not work... What am I doing wrong??

Please HELP:)

Answer 1

INotifyPropertyChange is working fine, since your code to Add a new item to the existing List does not actually re-assign a new value to the OrderList property (that is the set routine is never called) there is no call to NotifyPropertyChanged. Try it like this:-

public class Order : INotifyPropertyChanged 
{ 

    private String customerName; 

    public String CustomerName 
    { 
        get { return customerName; } 
        set {  
                customerName = value; 
                NotifyPropertyChanged("CustomerName"); 
            } 
    } 

    private ObservableCollection<String> orderList = new ObservableCollection<String>(); 

    public ObservableCollection<String> OrderList 
    { 
        get { return orderList; } 

    }  


    public void NotifyPropertyChanged(string propertyName) 
    { 
        if (PropertyChanged != null) 
        { 
            PropertyChanged(this, new PropertyChangedEventArgs(propertyName)); 
        } 
    }   
}

The ObservableCollection<T> type supports informing INotifyCollectionChanged which will inform the DataGrid when items are added to or removed from the collection.