private void Modificar_Proveedor_Click(object sender, RoutedEventArgs e)
        {
            try
            {
                object selected = dataGrid_Proveedor.SelectedItem;

                string id     = (dataGrid_Proveedor.SelectedCells[0].Column.GetCellContent(selected) as TextBlock).Text;
                string nombre = (dataGrid_Proveedor.SelectedCells[1].Column.GetCellContent(selected) as TextBlock).Text;
                string fono   = (dataGrid_Proveedor.SelectedCells[2].Column.GetCellContent(selected) as TextBlock).Text;
                string rubro  = (dataGrid_Proveedor.SelectedCells[3].Column.GetCellContent(selected) as TextBlock).Text;
                string modi   = (dataGrid_Proveedor.SelectedCells[0].Column.GetCellContent(selected) as TextBlock).Text;

                AgregarProveedoresWpf mpr = new AgregarProveedoresWpf();
                mpr.txt_numero_proveedor.Text    = id;
                mpr.txt_nombre_proveedor.Text    = nombre;
                mpr.txt_fono_proveedor.Text      = fono;
                mpr.txt_rubro_proveedor.Text     = rubro;
                mpr.txt_modificar_Proveedor.Text = modi;

                mpr.Show();
            }
            catch (Exception)
            {
                notifier.ShowWarning("Debe seleccionar el producto para  modificar");
            }
        }
        private void Btn_agregar_proveedor_Click(object sender, RoutedEventArgs e)
        {
            AgregarProveedoresWpf prove = new AgregarProveedoresWpf();

            prove.Show();
        }