private void dataGridView1_CellClick(object sender, DataGridViewCellEventArgs e)
{
if (dataGridView1.SelectedCells.Count > 1)
{
object valor = dataGridView1.SelectedCells[0].Value;
dataGridView1.SelectedCells[0].Value = dataGridView1.SelectedCells[1].Value;
dataGridView1.SelectedCells[1].Value = valor;
}
}