private void btn_group_Click(object sender, EventArgs e)
{
    //Applying grouping method to the listview collection
    listView1.SetItemsSource(cv, "Name", "City");
    cv.GroupAsync(v => v.City);
}

' Group data using GroupAsync method
Private cv As C1DataCollection(Of Customer)
Public Sub New()
    InitializeComponent()
    cv = New C1DataCollection(Of Customer)(Customer.GetCustomerList(100))
    listView1.SetItemsSource(cv, "Name")
    listView1.Visible = True
End Sub

Private Sub btn_group_Click(sender As Object, e As EventArgs) Handles btn_group.Click
    listView1.SetItemsSource(cv, "Name", "City")
    cv.GroupAsync(Function(v) v.City)
End Sub

// Group using GroupAsync method
private async void btn_group_Click(object sender, RoutedEventArgs e)
{
    var cv = new C1DataCollection<Customer>(Customer.GetCustomerList(100));
    await cv.GroupAsync("Country");
    var dv = new C1CollectionView(cv);
    listview1.ItemsSource = dv;
}

' Group using GroupAsync method
Private Async Function btn_group_ClickAsync(sender As Object, e As RoutedEventArgs) As Task Handles btn_group.Click
    Dim cv = New C1DataCollection(Of Customer)(Customer.GetCustomerList(100))
    Await cv.GroupAsync("Country")
    Dim dc = New C1CollectionView(cv)
    listview1.ItemsSource = dc
End Function

C1DataCollection<Customer> datacol;
public Grouping()
{
    InitializeComponent();

    var task = UpdateVideos();
}

private async Task UpdateVideos()
{
    var data = Customer.GetCustomerList(100);
    datacol = new C1DataCollection<Customer>(data);
    await datacol.GroupAsync(c => c.Country);
    grid.ItemsSource = datacol;
}

var grid = (FlexGrid)FindViewById(Resource.Id.Grid);
var data = Customer.GetCustomerList(250);

datacol = new C1GroupDataCollection<Customer>(data, false);
datacol.GroupAsync("Country");
grid.ItemsSource =datacol;

grid.SelectionMode = GridSelectionMode.Cell;
grid.ShowMarquee = true;
grid.AutoSizeColumns(0, grid.Columns.Count - 1);
grid.RowHeaders.Columns.Clear();
grid.Columns["Country"].IsVisible = false;

View.BackgroundColor = UIColor.White;
Title = "Grouping";
grid = new FlexGrid();
var data = Customer.GetCustomerList(100);
datacol = new C1DataCollection<Customer>(data);
datacol.GroupAsync("Country");
grid.ItemsSource = datacol;
grid.AllowDragging = GridAllowDragging.Both;
grid.AllowResizing = GridAllowResizing.Both;
grid.SelectionMode = GridSelectionMode.Cell;
grid.RowHeaders.Columns.Clear();
var _navbarHeight = this.NavigationController.NavigationBar.Bounds.Height + UIApplication.SharedApplication.StatusBarFrame.Height;
grid.Frame = new CGRect(this.View.Frame.X, this.View.Frame.Y + _navbarHeight, this.View.Frame.Width, this.View.Frame.Height - _navbarHeight);
this.View.AddSubview(grid);