How to collapse child control in listviewitem UWP

Question

Universal Windows Platform, C#

How can I collapse/expand the child listview of item MainListView listitem from code behind? I have not found anything that works. I\'

Answer 1

Here is how i would do it.

I would create two DataTemplates one to show when selected (Expanded), another when not expanded.

Below is my ViewModel.

public class MyViewModel
{
    public MyViewModel()
    {
        myItems = new ObservableCollection();
        for(int i=1;i<=10;i++)
        {
            MyItems item = new MyItems();
            item.Name = "Main Item " + i.ToString();
            ObservableCollection subItems = new ObservableCollection();
            for (int j=1;j<=5;j++)
            {
                subItems.Add(new MySubItems() { Title = "Sub Item " + j.ToString() });
            }
            item.Data = subItems;
            myItems.Add(item);
        }
    }

    public ObservableCollection myItems { get; set; }
}

public class MyItems
{
    public string Name { get; set; }
    public ObservableCollection Data { get; set; }
}

public class MySubItems
{
    public string Title { get; set; }
}

Below is my MainPage.xaml as requested

And Below is how my SelectionChanged Event Looks like.

private int PreviousIndex;
private void ListView_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
    ListView lv = sender as ListView;

    if (PreviousIndex >=0)
    {
        ListViewItem prevItem = (lv.ContainerFromIndex(PreviousIndex)) as ListViewItem;
        prevItem.ContentTemplate = Resources["NoSelectDataTemplate"] as DataTemplate;
    }

    ListViewItem item = (lv.ContainerFromIndex(lv.SelectedIndex)) as ListViewItem;
    item.ContentTemplate = Resources["SelectDataTemplate"] as DataTemplate;

    PreviousIndex = lv.SelectedIndex;
}

Here is the Output