Datagridview完整行选择但获取单个单元格值

private void dataGridView1_CellClick(object sender, DataGridViewCellEventArgs e)
{
    if (e.RowIndex >= 0)
    {
        DataGridViewRow row = dataGridView1.Rows[e.RowIndex];
        dataGridView1.ClearSelection();
        row.Selected = true;
        string cellValue = row.Cells[e.ColumnIndex].Value.ToString();
        MessageBox.Show("单元格值：" + cellValue);
    }
}