How can I make it so my field is only set the one time?
<p>I have a field in my model class that's coded as follows:</p>

<pre><code>    public string CreatedBy
    {
        get { return _CreatedBy; }
        set { _CreatedBy = value; Created = DateTime.Now; }
    }
    public DateTime? Created { get; set; }
</code></pre>

<p>When the CreatedBy field is populated then it fills out the Created date automatically. The problem for me is that if I again set the CreatedBy field (yes it can happen) then the date gets updated with the current date again.</p>

<p>Is there a way that I can make it so the CreatedBy and the Created fields can be populated just once?</p>
