how to detect grid view empty cell
<p><strong>how to detect grid view empty cell ?</strong>  I need it for highlighting. So I made a css </p>

<pre><code>.RedColored 
{
    background: FF0000;
}
</code></pre>

<p>and trying to appear it to empty GV cells this way :   </p>

<pre><code>protected virtual GridView1_RowDataBound (_sender : object,  e : System.Web.UI.WebControls.GridViewRowEventArgs) : void
        {
            e.Row.Cells[0].CssClass = "wide";
            foreach(i : int in [0..e.Row.Cells.Count-1])
            {
                when(e.Row.Cells[i].Text==null)
                {
                    e.Row.Cells[i].CssClass="RedColored";
                }
            }
        } 
</code></pre>

<p>but my it doesn't appears to empty cells , even I've tried 
Text=="" , Cell[i]==null, Cell[i].ToString()=="" and nothing helped.</p>

<pre><code>recoded to :            

def IsCellNull(cell : TableCell) : bool
            {
                | null =&gt; true
                | c =&gt; string.IsNullOrEmpty(c.ToString()) || c.GetType().Name == "DBNull"
        }

            foreach(i : int in [0..e.Row.Cells.Count-1])
            {
                when(IsCellNull(e.Row.Cells[i]))
                {
                    e.Row.Cells[i].Text="BLABLA";
                    e.Row.Cells[i].CssClass="RedColored";
                }
            }
</code></pre>

<blockquote>
  <p><strong>But !!! It even doesn't helped , it works without WHEN, but when (if) can not find empty cells :P</strong>
  Finally : solved with this code :`            e.Row.Cells[0].CssClass = "wide";</p>
</blockquote>

<pre><code>        def IsCellNull(cell : TableCell) : bool
        {
            | null =&gt; true
            | c =&gt; string.IsNullOrEmpty(c.ToString()) 
            || c.GetType().Name == "DBNull" 
            || c.Text=="&amp;nbsp;"
        }

        foreach(i : int in [0..e.Row.Cells.Count-1])
        {
            when(IsCellNull(e.Row.Cells[i]))
            {
                e.Row.Cells[i].BackColor=System.Drawing.Color.Red;
            }
        }`
</code></pre>
