How to make ListBox editable when bound to a List?

Question

Edit: The basic problem is binding a List to ListBox(or any other control). So I am editing the question.

I bound a list of string to a ListBox as b

Answer 1

The DataContext of each ListBoxItem is the string itself, so the path of your binding is empty (.). TwoWay and OneWayToSource bindings require a path, since you can't just replace the current DataContext. So you need to wrap your string in an object that exposes the string as a property:

public class StringItem
{
    public string Value { get; set; }
}

Expose the strings as a list of StringItem:

public partial class MainWindow : Window
{
    List _nameList = null;

    public List NameList
    {
        get
        {
            if (_nameList == null)
            {
                _nameList = new List();
            }
            return _nameList;
        }
        set
        {
            _nameList = value;
        }
    }
    public MainWindow()
    {
        NameList.Add(new StringItem { Value = "test1" });
        NameList.Add(new StringItem { Value = "test2" });
        InitializeComponent();
    }

And bind to the Value property:

Note that StringItem will also need to implement INotifyPropertyChanged so that bindings are automatically updated. You should also expose the list as an ObservableCollection rather than a List