How to get ListBox ItemsPanel in code behind

Question

I have a ListBox with an ItemsPanel

Answer 1

You can use the Loaded event for the StackPanel that is in the ItemsPanelTemplate

And then in code behind

private StackPanel m_itemsPanelStackPanel;
private void StackPanel_Loaded(object sender, RoutedEventArgs e)
{
    m_itemsPanelStackPanel = sender as StackPanel;
}

Another way is to traverse the Visual Tree and find the StackPanel which will be the first child of the ItemsPresenter.

public void SomeMethod()
{
    ItemsPresenter itemsPresenter = GetVisualChild(listBox);
    StackPanel itemsPanelStackPanel = GetVisualChild(itemsPresenter);
}

private static T GetVisualChild(DependencyObject parent) where T : Visual
{
    T child = default(T);

    int numVisuals = VisualTreeHelper.GetChildrenCount(parent);
    for (int i = 0; i < numVisuals; i++)
    {
        Visual v = (Visual)VisualTreeHelper.GetChild(parent, i);
        child = v as T;
        if (child == null)
        {
            child = GetVisualChild(v);
        }
        if (child != null)
        {
            break;
        }
    }
    return child;
}