hi,
First of all in code, you do not need to exclusively check for the state of the control, when you are assigning just true or false, it could be as simple as:
private void cb_am_CheckedChanged(object sender, EventArgs e)
{
dataGridView1.Rows[0].Cells[0].Value = cb_am.Checked;
dataGridView1.Rows[0].Cells[1].Value = cb_am.Checked;
}
you are basically assigning the state of the radio button to the checkbox in the cell.
Second, radio button are not like check boxes, to change the state of one radio button, an another radio button must be "Checked = true;", so you need at least two radio buttons to check and uncheck your check boxes in those cells.
Third, you are only setting the state of the check boxes in the CheckChanged event of the cb_am control, some times this control may not change its state, such as if you have three radio buttons, cb_am, cb_am1 and cb_am2, if the state of the radio button changes from cb_am1 to cb_am2, the cb_am will not trigger the CheckChanged event, so the checkboxes in those cells will not be updated.
I hope this helps.
Regards
Jegan