如何根据C＃中的值更改单元格的颜色

Question

当我的值小于100时，我试图让细胞改变颜色但是它不会改变细胞的颜色。我可以默认整个网格的颜色，但它不适用于单个单元格。请有人伸出援手吗？

这是我到目前为止的代码：

            connection.Open();
            var SinglesDataTable = new DataTable();
            adapter.Fill(SinglesDataTable);
            connection.Close();
            DataColumn hourlyavg = SinglesDataTable.Columns.Add("Hourly Average", typeof(String));

            for (int i = 0; i < SinglesDataTable.Rows.Count; i++)
            {
                object pickvalue = SinglesDataTable.Rows[i][1].ToString();
                object timevalue = SinglesDataTable.Rows[i][2].ToString();
                double pickval1 = Convert.ToDouble(pickvalue);
                string timeS = "";
                timeS = timevalue.ToString();
                string timeSTrimmed = (timeS.Replace(":", ""));
                string timeSTrimmedHoursMins = (timeSTrimmed.Remove(timeSTrimmed.Length - 2));
                string timehourminindecimal = timeSTrimmedHoursMins.Insert(2, ".");
                double timeint = Convert.ToDouble(timehourminindecimal);
                if (timeint < 1)
                {
                    timeint = Math.Ceiling(timeint);

                }
                else
                {
                    timeint = timeint;
                }
                Convert.ToInt32(pickvalue);
                var hourlyratevar = pickval1 / timeint;
                double hourlyratedouble = Math.Round(hourlyratevar, 2);
                int hourlyraterounded = (int)Math.Ceiling(hourlyratedouble);
                SinglesDataTable.Rows[i][3] = hourlyraterounded;



                string hourlyavgstring = SinglesDataTable.Rows[i][3].ToString();
                double hourlyavgint = Convert.ToDouble(hourlyavgstring);


                foreach (DataGridViewRow row in SinglesGridView.Rows)
                    if (Convert.ToInt32(row.Cells[1].Value) > 100)
                    {
                        row.DefaultCellStyle.BackColor = Color.Red;
                    }

                SinglesGridView.DataSource = SinglesDataTable;

Answer 1

 foreach (DataGridViewRow row in SinglesGridView.Rows)
    if (Convert.ToInt32(row.Cells[1].Value) > 100)
        row.Cells[1].Style.BackColor = Color.Red;

还有另一种选择：处理DataGridView的CellPainting事件。 E.g：

private void SinglesGridView_CellPainting(object sender,
System.Windows.Forms.DataGridViewCellPaintingEventArgs e)
{
    if (e.ColumnIndex == 1 && 
        e.RowIndex >= 0 &&
        Convert.ToInt32(SinglesGridView[e.ColumnIndex, e.RowIndex].Value) > 100)
    e.CellStyle.BackColor = Color.Red;
}