Programming with .NET - General

Re: Update ListBox Dynamically when underlying data changed

esite — Fri, 03 Jul 2009 09:31:53 GMT

Re: Re: Update ListBox Dynamically when underlying data changed

esite — Thu, 02 Jul 2009 11:55:03 GMT

Thanks varshavmane and HarshBardhan the key is that ObservableCollection. Appreciate your efforts.

Re: Update ListBox Dynamically when underlying data changed

HarshBardhan — Thu, 02 Jul 2009 11:14:53 GMT

I had modified few things in your sample.

You can try this.

//Xaml file

//Code behind:

    public partial class Page : UserControl
    {
        ObservableCollection users;
     
        public Page()
        {
            InitializeComponent();

  users = new ObservableCollection();
            users.Add(new User() { UserName = "Harsh" });
            users.Add(new User() { UserName = "Nimesh" });
            users.Add(new User() { UserName = "Test" });
            users.Add(new User() { UserName = "Test1" });
            users.Add(new User() { UserName = "Test2" });

            Chapters.ItemsSource = users;


}

        private void btnDeleteList_Click(object sender, RoutedEventArgs e)
        {
            if (users.Count > 2)
            {
                users.RemoveAt(2);
            }
        } 
       
    


 

    }

    public class User: INotifyPropertyChanged
    {
       private string   username  ;

    public string  UserName
    {
         get 
         {
             return  username ; 
         }
         set 
         {
            

              username  = value;
                 onPropertyChanged( this ,  "UserName" ) ;
             }
        }

        public event   PropertyChangedEventHandler PropertyChanged  ;

    private void  onPropertyChanged( object  sender ,  string  propertyName)
    {

         if  ( this.PropertyChanged != null )
        {
            PropertyChanged(sender, new  PropertyChangedEventArgs(propertyName)) ;
         }
    }
    }

It uses observable collection concept.

Re: Update ListBox Dynamically when underlying data changed

varshavmane — Thu, 02 Jul 2009 11:01:17 GMT

Use ObservableCollection.

Have a quick look around - see if this link helps...

HTH

Update ListBox Dynamically when underlying data changed

esite — Thu, 02 Jul 2009 10:27:10 GMT

A rookie question here I am sure. I adapted this tutorial as an example (http://silverlight.net/learn/tutorials/databinding.aspx).

When I delete a record from the bound data of ListBox the list box is not updated. I have no idea how to make it change it's datasource once it is deleted.

So I adapted the tutorial to have a delete chapter button like this and the Listbox to bind TwoWay:

private void btnDeleteList_Click(object sender, RoutedEventArgs e)
{
    currentBook.Chapters.Remove(Chapters.SelectedItem.ToString());
    //Chapters.ItemsSource = Chapters;
    //Chapters.SetBinding(ListBox.DataContextProperty, new Binding("Chapters"));
}

I would expect or know how to be able to update the Listbox immediately once I click delete the Chapter.

Any help would be greatly appreciated.

Thanks.