How can I change the background color of a gridview cell, based on a conditional statement?

Question

Okay I clearly haven't fed google the right query or I would've found out by now. I'm hoping someone on this forum can help me.

So I have a datatable that I'm adding rows to based on a datareader that's getting its info from an sql query executed over a database. So far, so good. Now, one of those columns is called 'analysis', and I need its background color to be green if the preceding two columns are matched, and red otherwise.

If I can't touch the background color, I'd like to insert a special character, any javascript that isn't interpreted as text.

Simply put, I'd like css control over a gridview from codebehind. I've looked and looked to no avail. I found this guy, but I haven't checked if his solution works on an ASP.Net/C# website. Any ideas?

Macaroon

Answer 1

In the GridView_RowDataBound event, get the cell you want to change the back-color, set the color of the cell if your condition is tested true.

/// <summary>
/// Handles gridview row data bound event.
/// </summary>
/// <param name="sender">Sender Object</param>
/// <param name="e">Event Argument</param>
protected void Gv_RowDataBound(object sender, GridViewRowEventArgs e)
{
    // We don’t want to apply this to headers.
    if (e.Row.RowType == DataControlRowType.DataRow)
    {
        try
        {
            //your data-object that is rendered in this row, if at all required.
            //Object obj = e.Row.DataItem;

            //find the right color from condition
            string color = condition ? "#ff9900" : "some-other-color";

            //set the backcolor of the cell based on the condition
            e.Row.Cells[4].Attributes.Add("Style", "background-color: " + color + ";");
        }
        catch
        {
        }
    }
}

Alaric

Answer 2

 protected void GVKeywordReport_RowDataBound(object sender, GridViewRowEventArgs e)
        {

            if (e.Row.RowType == DataControlRowType.DataRow)
            {
                DataRow pr = ((DataRowView)e.Row.DataItem).Row;
                int oldPos = Convert.ToInt32(pr["oldposition"]);
                int newPos = Convert.ToInt32(pr["newposition"]);
                GVKeywordReport.HeaderRow.Cells[3].Text = txtfrmdate.Text;
                GVKeywordReport.HeaderRow.Cells[4].Text = txtEndDate.Text;

                GVKeywordReport.HeaderRow.BackColor = ColorTranslator.FromHtml("#B3B300");
                e.Row.Cells[0].BackColor = ColorTranslator.FromHtml("#B3B300");
                e.Row.Cells[5].BackColor = ColorTranslator.FromHtml("#FFFFFF");

                if (oldPos == newPos)
                {
                    e.Row.BackColor = ColorTranslator.FromHtml("#FF950E");
                    e.Row.Cells[6].Text = "No Change";
                }
                else if (oldPos > newPos)
                {
                    e.Row.BackColor = ColorTranslator.FromHtml("#FFFFCC");
                    e.Row.Cells[6].Text = "Improved";
                }
                else  

                {
                    e.Row.BackColor = ColorTranslator.FromHtml("#FF0000");
                    e.Row.Cells[6].Text = "Decreased";
                }
               // e.Row.Cells[0].BackColor = ColorTranslator.FromHtml("#7DA647");
            }
        }

Callipygian

While this code block may answer the question, it would be best if you could provide a little explanation for why it does so – Atropos