LongListSelector: Item tap?

Question

I am using LongListSelector control on Windows Phone 8 and can't figure out the best way to handle a tap on an item. The few examples I've found rely on the SelectionChanged event. However, this solution is buggy because if I tap an item that opens a new page, hit back, and then tap the same item again, it won't work because this item is already selected, so SelectionChanged is not triggered.

I tried to register to the tap event and use the current selected item as the tapped one, but some times the current selected item is not the one I expect.

I could wrap my ItemTemplate in a button and handle the tap for each item but I need to reskin the button to make it look like a simple list item.

Finally, I don't understand why it is so complicated to achieve such a basic thing. Is there a simple and standard way I missed?

My second wish is to get an effect on the item when it is tapped. Is there any standard way to do it?

Answer 1

You could null your LongListSelector's SelectedItem at the end of each SelectionChanged event. I.e.

<phone:LongListSelector x:Name="LLS" SelectionChanged="LLS_SelectionChanged"> 

And the event handler:

private void LLS_SelectionChanged(object sender, SelectionChangedEventArgs e) {    // If selected item is null, do nothing   if (LLS.SelectedItem == null)     return;    // Navigate to the next page   NavigationService.Navigate(new Uri("/nextpage.xaml", UriKind.Relative));    // Reset selected item to null   LLS.SelectedItem = null; } 

You'll fire the SelectionChanged event twice, but nothing's going to happen the second time round and you should get the behaviour that you're looking for - (i.e Setting SelectedItem to null will trigger a new SelectionChanged event, but this second event gets caught in the if-statement)

As for the second part of your question, you might be better posting a new question.

Answer 2

I done it with the Tap event handling.

I prefer not to use Selected property, but get tapped item this way (and I haven't noticed any bugs):

MyListItemClass item = ((FrameworkElement)e.OriginalSource).DataContext                                                               as MyListItemClass; 

Also, you could get the original item ContentPresenter simple by navigating up through VisualTree from e.OriginalSource. That way:

ContentPresenter itemPresenter = SomeHelperClass                               .FindParent<ContentPresenter>(e.OriginalSource,""); 

Where FindParent is similar to find child in this question: How can I find WPF controls by name or type?

ContentPresenter is that object what you need to manually change the item template if you want to (to set "selected" state for example).