How can I detect changes to item properties in the BindingList?

Question

I have a custom class Foo with properties A and B. I want to display it in a databinding control.

I have created a class Foos : BindingList .

Answer 1

Foo should implement the INotifyPropertyChanged and INotifyPropertyChanging interfaces.

public void Foo : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    private void NotifyPropertyChanged(String info)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(info));
        }
    }

    private int _someValue;
    public int SomeValue
    {
        get { return _someValue; }
        set { _someValue = value; NotifyPropertyChanged("SomeValue"); }
    }
}

The BindingList should hook onto your event handler automatically, and your GUI should now update whenever you set your class invokes the PropertyChanged event handler.

[Edit to add:] Additionally, the BindingList class expose two events which notify you when the collection has been added to or modified:

public void DoSomething()
{
    BindingList<Foo> foos = getBindingList();
    foos.ListChanged += HandleFooChanged;
}

void HandleFooChanged(object sender, ListChangedEventArgs e)
{
    MessageBox.Show(e.ListChangedType.ToString());
}