OnRowCreated="gridStatistic_RowCreated

     private void FillUI()

        {

            gridStatistic.DataSource = dtStatistic;

            gridStatistic.DataBind();

        }

 protected void gridStatistic_RowCreated(object sender, GridViewRowEventArgs e)

        {

            if (e.Row.RowIndex > -1)

            {

                if (dtStatistic != null && dtStatistic.Rows.Count > 0)

                {

                    decimal InfoReward = Convert.ToDecimal(dtStatistic.Rows[e.Row.RowIndex].ItemArray[dtStatistic.Columns.IndexOf("InfoReward")]);

                    decimal InfoMoney = Convert.ToDecimal(dtStatistic.Rows[e.Row.RowIndex].ItemArray[dtStatistic.Columns.IndexOf("InfoMoney")]);

                    if (InfoMoney > InfoReward)

                    {

                        e.Row.Cells[3].ForeColor = System.Drawing.Color.Red;

                    }

                }

            }

        }

---------------或：---decimal数值对比--

 protected void gridStatistic_RowCreated(object sender, GridViewRowEventArgs e)

        {

            if (e.Row.RowIndex > -1)

            {

                if (dtStatistic != null && dtStatistic.Rows.Count > 0)

                {

                    decimal InfoReward  = Convert.ToDecimal(dtStatistic.Rows[e.Row.RowIndex].ItemArray[dtStatistic.Columns.IndexOf("InfoReward")]);

                    decimal InfoMoney = Convert.ToDecimal(dtStatistic.Rows[e.Row.RowIndex].ItemArray[dtStatistic.Columns.IndexOf("InfoMoney")]);

                    decimal cs = InfoMoney - InfoReward;

                    if (cs>0)

                    {

                        e.Row.Cells[3].ForeColor = System.Drawing.Color.Red;

                    }

                }

            }

        }

--------------

 protected void gridStatistic_RowCreated(object sender, GridViewRowEventArgs e)

        {

            if (e.Row.RowIndex > -1)

            {

                if (dtStatistic != null && dtStatistic.Rows.Count > 0)

                {

                    string InfoMoney="";

                    decimal InfoReward  = Convert.ToDecimal(dtStatistic.Rows[e.Row.RowIndex].ItemArray[dtStatistic.Columns.IndexOf("InfoReward")]);

                    InfoMoney = Convert.ToString(dtStatistic.Rows[e.Row.RowIndex].ItemArray[dtStatistic.Columns.IndexOf("InfoMoney")]);

                    if (InfoMoney == "")

                        InfoMoney ="0";

                    if (Convert.ToDecimal(InfoMoney) > InfoReward)

                    {

                        e.Row.Cells[3].ForeColor = System.Drawing.Color.Red;

                    }

                }

            }

        }