how to change DataGridViewCheckBoxCell checked state by code
<pre><code>  foreach (DataGridViewRow dgvr in dataGridViewProductList.Rows)
                {
                    string dgvrID = dgvr.Cells["ID"].Value.ToString();
                    DataRow[] s = DT.Select("BillID = " + dgvrID);
                    if (s.Length &gt; 0)
                    {
                        dataGridViewProductList.Columns["chk"].ReadOnly = false;
                        dataGridViewProductList.Rows[dgvr.Index].Cells["chk"].ReadOnly = false;
                         dataGridViewProductList.Rows[dgvr.Index].Cells["chk"].Value = 1;
        }
    }
</code></pre>

<p>after running code <code>DataGridViewCheckBoxCell</code> doesn't changed to checked, how can i  change its checked state</p>

<p>i tried </p>

<pre><code>DataGridViewCheckBoxCell cell = (DataGridViewCheckBoxCell)dataGridViewProductList.Rows[dgvr.Index].Cells["chk"];
                         cell.ReadOnly = false;
                        cell.TrueValue = true;

                        cell.Value = cell.TrueValue;
</code></pre>

<p>but doesn't work.</p>