private void dataGridView1_CellMouseClick(object sender, DataGridViewCellMouseEventArgs e)
{
if (opcion > 0)
{
string valor = dataGridView1.Rows[dataGridView1.CurrentRow.Index].Cells[0].Value.ToString();
if (valor != null)
{
Libros u = udao.ObtenerLibro(valor);
nu.Text = u.idlibro.ToString();
n1.Text = u.titulo;
n2.Text = u.editorial;
a1.Text = u.autor;
pictureBox1.Image = u.portada.Image;
}
}
}