How to scrolling up and down using Incremental Loading Collection in a list view using UWP?

To enable scrolling up and down using Incremental Loading Collection in a ListView in UWP (Universal Windows Platform), you can follow these steps:

1. Create a new class that implements the ISupportIncrementalLoading interface. This interface requires implementing two methods: HasMoreItems and LoadMoreItemsAsync. The HasMoreItems method checks if there are more items to load, while the LoadMoreItemsAsync method loads the next set of items. Here's an example implementation:

csharpCopy code
public class IncrementalDataSource : ObservableCollection<object>, ISupportIncrementalLoading

{

    private int currentPage = 0;

    private int pageSize = 20; // Number of items to load per page



    public bool HasMoreItems { get; private set; }



    public IAsyncOperation<LoadMoreItemsResult> LoadMoreItemsAsync(uint count)

    {

        return AsyncInfo.Run(async c =>

        {

            var items = await GetItemsAsync();

            if (items != null && items.Any())

            {

                foreach (var item in items)

                {

                    Add(item);

                }



                currentPage++;

            }



            HasMoreItems = currentPage < MaxPages; // Check if there are more pages to load



            return new LoadMoreItemsResult { Count = (uint)items.Count() };

        });

    }



    private async Task<IEnumerable<object>> GetItemsAsync()

    {

        // Implement your logic to load the next set of items from a data source

        // You can use currentPage and pageSize variables to control the range of items to load

    }

}

1. In your XAML, define a ListView control and bind it to your IncrementalDataSource class. Set the ItemsSource property of the ListView to the IncrementalDataSource instance.

xamlCopy code
<ListView x:Name="myListView" 

          ItemsSource="{Binding}"

          IsItemClickEnabled="False"

          ScrollViewer.VerticalScrollBarVisibility="Auto"

          ScrollViewer.VerticalScrollMode="Enabled">

    <!-- Add necessary ListView.ItemTemplate and ListView.ItemContainerStyle -->

</ListView>

1. In your code-behind or ViewModel, create an instance of the IncrementalDataSource class and set it as the DataContext of the ListView.

csharpCopy code
var incrementalDataSource = new IncrementalDataSource();

myListView.DataContext = incrementalDataSource;

Now, when you run your UWP application, the ListView will load items incrementally as the user scrolls up or down. The LoadMoreItemsAsync method in the IncrementalDataSource class will be called automatically to load the next set of items when the user scrolls to the end of the ListView.