how to send event when Collection is modified?
<p>Sorry I'm newbie in C# and events especially.
Why I receive NPE?</p>

<pre><code>class WcfModel : IWcfModel
{
    private List&lt;ConsoleData&gt; _dataList;

    public List&lt;ConsoleData&gt; DataList
    {
        get { return _dataList; }
        set { _dataList = value;
            DataArrived(_dataList);  // NPE
        }
    }

    public event Action&lt;List&lt;ConsoleData&gt;&gt; DataArrived;
}
</code></pre>
