CapDemo.GUI.User_Controls.ImportQuestions.chk_CheckAll_CheckedChanged C# (CSharp) Метод

        private void chk_CheckAll_CheckedChanged(object sender, EventArgs e)
        {
            if (chk_CheckAll.Checked == true)
            {
                foreach (DataGridViewRow row in dataGridView1.Rows)
                {
                    if (row.ReadOnly==false)
                    {
                        row.Cells["Check"].Value = true;
                    }

                }
            }
            else
            {
                foreach (DataGridViewRow row in dataGridView1.Rows)
                {
                    if (row.ReadOnly==false)
                    {
                        row.Cells["Check"].Value = null;
                    }
                }
            }
        }