Changing datagridview cell color based on condition

Question

I have loaded the data from database to datagridview and have two columns target value and volume where volume >target value that volume cell should be in green color and

Answer 1

Let's say you have to color certain cell (not all cells of the row) by knowing two things:

1. Name or index of the column.
2. Value which is gonna be inside of the cell.

In thas case you have to use event CellFormatting

In my case I use like this

private void DgvTrucksMaster_CellFormatting(object sender, DataGridViewCellFormattingEventArgs e)
{
     foreach (DataGridViewRow row in dgvTrucksMaster.Rows)
     {
       if (Convert.ToInt32(row.Cells["Decade1Hours"].Value) > 0)
       {
          row.Cells["Decade1Hours"].Style.BackColor = Color.LightGreen;
       }
       else if (Convert.ToInt32(row.Cells["Decade1Hours"].Value) < 0)
       {
          // row.DefaultCellStyle.BackColor = Color.LightSalmon; // Use it in order to colorize all cells of the row

          row.Cells["Decade1Hours"].Style.BackColor = Color.LightSalmon;
       }
     }
}

And result you can see here

So here you can access certain cell of the row in column by its name row.Cells["Decade1Hours"]

How do you know this name? Well in my case i create column of DataGridView like this.

var Decade1Hours = new DataGridViewTextBoxColumn()
{
   Name = "Decade1Hours",
   Width = 50,
   DataPropertyName = "Decade1Hours",
   ReadOnly = true,
   DefaultCellStyle = new DataGridViewCellStyle()
       {
        Alignment = DataGridViewContentAlignment.MiddleCenter,
        ForeColor = System.Drawing.Color.Black,
        Font = new Font(font, FontStyle.Bold),
        Format = "n2"
      },
   HeaderCell = new DataGridViewColumnHeaderCell()
      {
          Style = new DataGridViewCellStyle()
               {
                 Alignment = DataGridViewContentAlignment.MiddleCenter,
                 BackColor = System.Drawing.Color.Blue
               }
       }
};
Decade1Hours.HeaderText = "Дек.1";
dgvTrucksMaster.Columns.Add(Decade1Hours);

And well... you you need for instance colorize some of the cells in the row like ##1 4 5 and 8 you have to use cell index (it starts from 0).

And code will lok like

 private void DgvTrucksMaster_CellFormatting(object sender, DataGridViewCellFormattingEventArgs e)
{
  foreach (DataGridViewRow row in dgvTrucksMaster.Rows)
  {
    if (Convert.ToInt32(row.Cells[1].Value) > 0 )
    {
      row.Cells[1].Style.BackColor = Color.LightGreen;
    }
  }
}