以编程方式更改WPF Datagrid Row背景颜色

Question

I'm facing issues when trying to change a DataGrid row in the code behind of a WPF app. My objective is to change the row color when the row is selected and when a button Valider is clicked. My code is shown below. I found some answers but none of them where useful for my case.

 private void Valider_Click(object sender, RoutedEventArgs e)
    {
        DataGridRow dataGridRow = InventaireItemGrid.SelectedItem as DataGridRow;

         dataGridRow.Background = Brushes.Green;
      }

When I execute, I get a NullReferenceException . The debugger point to the dataGridRow to be null (the row contains data though).

Answer 1

The SelectedItem property refers to the corresponding object in the Items collection. You could use the ItemContainerGenerator to get a reference to the DataGridRow container:

private void Valider_Click(object sender, RoutedEventArgs e)
{
    DataGridRow dataGridRow = InventaireItemGrid.ItemContainerGenerator.ContainerFromItem(InventaireItemGrid.SelectedItem) as DataGridRow;
    if (dataGridRow != null)
        dataGridRow.Background = Brushes.Green;
}

There are most probably better ways of doing whatever you are trying to do though, for example using data binding and triggers.