Question

how to detect grid view empty cell ? I need it for highlighting. So I made a css

.RedColored 
{
    background: FF0000;
}

and trying to appear it to empty GV cells this way :

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";
                }
            }
        } 

but my it doesn’t appears to empty cells , even I’ve tried
Text==”” , Cell[i]==null, Cell[i].ToString()==”” and nothing helped.

recoded to :            

def IsCellNull(cell : TableCell) : bool
            {
                | null => true
                | c => 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";
                }
            }

But !!! It even doesn’t helped , it works without WHEN, but when (if) can not find empty cells 😛
Finally : solved with this code :` e.Row.Cells[0].CssClass = “wide”;

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

        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;
            }
        }`

Answer 1

In some browsers, the cell will not display a color if it is empty. Adding a space in it solves this issue, but then it will no longer be empty…

To test a cell, you should use string.IsNullOrEmpty():

when(string.IsNullOrEmpty(e.Row.Cells[i].Text))
{
  e.Row.Cells[i].Text=" "; // Or sometimes a no break space -   will work better
  e.Row.Cells[i].CssClass="RedColored";
}