private async void GridViewPages_Loaded(object sender, RoutedEventArgs e)
{
await RunOnUIThreadAsync(CoreDispatcherPriority.High, () =>
{
if (GridViewPages.Items.Count >= 1)
{
int index = ViewModel.SelectedPageIndex;
// fix GridView initially fails to select item by binding
GridViewPages.SelectedIndex = index;
// try scroll to selected item
try
{
GridViewItem item = (GridViewItem)GridViewPages.ContainerFromIndex(index);
Guard.IsNotNull(item, nameof(item));
BringIntoViewOptions options = new BringIntoViewOptions
{
AnimationDesired = false,
};
item.StartBringIntoView(options);
}
catch (Exception exc)
{
ViewModel.AppCenterService.TrackError(exc);
}
}
});
}
private async void GridViewPages_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
await RunOnUIThreadAsync(CoreDispatcherPriority.Normal, () =>
{
if (GridViewPages.SelectionMode == ListViewSelectionMode.Single &&
e.AddedItems != null & e.AddedItems.Count != 0)
{
// select page in view model
ViewModel.SelectedPageIndex = GridViewPages.SelectedIndex;
// scroll to newly selected item
try
{
GridViewItem item = (GridViewItem)GridViewPages.ContainerFromItem(e.AddedItems[0]);
BringIntoViewOptions options = new BringIntoViewOptions
{
AnimationDesired = true,
};
item.StartBringIntoView(options);
}
catch (Exception)
{
}
}
else if (GridViewPages.SelectionMode == ListViewSelectionMode.Single)
{
try
{
GridViewPages.SelectedIndex = ViewModel.SelectedPageIndex;
}
catch (Exception) { }
}
else if (GridViewPages.SelectionMode != ListViewSelectionMode.Single)
{
// connect items to view model
if (GridViewPages.SelectedRanges.Count == 0)
{
ViewModel.SelectedRanges = null;
}
else
{
ViewModel.SelectedRanges = GridViewPages.SelectedRanges;
}
// select last selected item in view model
if (e.AddedItems != null && e.AddedItems.Count != 0)
{
int index = GridViewPages.Items.IndexOf(e.AddedItems[e.AddedItems.Count - 1]);
ViewModel.SelectedPageIndex = index;
}
}
});
}
private void ListView_PreviewKeyDown(object sender, KeyRoutedEventArgs e)
{
list.UpdateLayout();
if (listIndexsInEachRiver == null)
{
//Stores all gridviews(one row enabled)
listRivers = TreeHelper.FindVisualChildren<GridView>(list);
//Stores the selected index item of each river
listIndexsInEachRiver = new List<int>();
foreach (var item in listRivers)
{
listIndexsInEachRiver.Add(item.SelectedIndex);
}
}
//Declare:
//Each river contains a title and a gridview(one row enabled). Remember it!!!
//Current river
var listItem = list.ContainerFromIndex(riverIndexInAllRivers) as ListViewItem;
//Current GridView in current river
var currentRiver = TreeHelper.FindVisualChild<GridView>(listItem);
Debug.WriteLine("currentRiver.ActualWidth: " + currentRiver.ActualWidth);
//Current item index in current river
int itemIndexInCurrentRiver = currentRiver.SelectedIndex;
//Current river index in all rivers
//int riverIndexInCurrentRivers = listRivers.IndexOf(currentRiver);
switch (e.Key)
{
case VirtualKey.Down:
case VirtualKey.GamepadDPadDown:
case VirtualKey.GamepadLeftThumbstickDown:
if (riverIndexInAllRivers + 1 < listRivers.Count)
{
var nextRiver = listRivers[riverIndexInAllRivers + 1];
nextRiver.Focus(FocusState.Programmatic);
if (nextRiver.Items != null && nextRiver.Items.Count > 0)
{
GridViewItem item = new GridViewItem();
if (listIndexsInEachRiver[riverIndexInAllRivers + 1] == -1)
{
item = nextRiver.ContainerFromIndex(0) as GridViewItem;
listIndexsInEachRiver[riverIndexInAllRivers + 1] = 0;
}
else
{
item = nextRiver.ContainerFromIndex(listIndexsInEachRiver[riverIndexInAllRivers + 1]) as GridViewItem;
listIndexsInEachRiver[riverIndexInAllRivers] = itemIndexInCurrentRiver;
}
item.Focus(FocusState.Programmatic);
item.IsSelected = true;
item.StartBringIntoView();
}
riverIndexInAllRivers++;
}
e.Handled = true;
break;
case VirtualKey.Up:
case VirtualKey.GamepadDPadUp:
case VirtualKey.GamepadLeftThumbstickUp:
if (riverIndexInAllRivers - 1 >= 0)
{
var previousRiver = listRivers[riverIndexInAllRivers - 1];
previousRiver.Focus(FocusState.Programmatic);
if (previousRiver.Items != null && previousRiver.Items.Count > 0)
{
GridViewItem item = new GridViewItem();
if (listIndexsInEachRiver[riverIndexInAllRivers - 1] == -1) //Probably never happen
{
item = previousRiver.ContainerFromIndex(0) as GridViewItem;
listIndexsInEachRiver[riverIndexInAllRivers] = 0;
}
else
{
item = previousRiver.ContainerFromIndex(listIndexsInEachRiver[riverIndexInAllRivers - 1]) as GridViewItem;
listIndexsInEachRiver[riverIndexInAllRivers] = itemIndexInCurrentRiver;
}
item.Focus(FocusState.Programmatic);
item.IsSelected = true;
item.StartBringIntoView();
}
riverIndexInAllRivers--;
}
e.Handled = true;
break;
case VirtualKey.Left:
case VirtualKey.GamepadDPadLeft:
case VirtualKey.GamepadLeftThumbstickLeft:
if (itemIndexInCurrentRiver - 1 >= 0)
{
currentRiver.Focus(FocusState.Programmatic);
GridViewItem item = new GridViewItem();
item = currentRiver.ContainerFromIndex(listIndexsInEachRiver[riverIndexInAllRivers]) as GridViewItem;
listIndexsInEachRiver[riverIndexInAllRivers] = itemIndexInCurrentRiver - 1;
item.Focus(FocusState.Programmatic);
item.IsSelected = true;
item.StartBringIntoView();
e.Handled = false;
}
else
e.Handled = true;
break;
case VirtualKey.Right:
case VirtualKey.GamepadDPadRight:
case VirtualKey.GamepadLeftThumbstickRight:
if (itemIndexInCurrentRiver + 1 <= currentRiver.Items.Count - 1)
{
currentRiver.Focus(FocusState.Programmatic);
GridViewItem item = new GridViewItem();
item = currentRiver.ContainerFromIndex(listIndexsInEachRiver[riverIndexInAllRivers]) as GridViewItem;
listIndexsInEachRiver[riverIndexInAllRivers] = itemIndexInCurrentRiver + 1;
item.UpdateLayout();
item.Focus(FocusState.Programmatic);
item.IsSelected = true;
item.StartBringIntoView();
e.Handled = false;
}
else
e.Handled = true;
break;
default:
break;
}
}