private async void Scroll_ViewChanged(object sender, ScrollViewerViewChangedEventArgs e)
{
if (!e.IsIntermediate)
{
var Sender = sender as ScrollViewer;
if (Sender.ScrollableHeight - Sender.VerticalOffset == 0)
{
var CurrentCategory = this.DefaultViewModel[Item] as Category;
if (CurrentCategory.NextPageUri == null)
{
this.Scroll.ViewChanged -= Scroll_ViewChanged;
}
else
{
lock (IncrementalLoadingHelper)
{
if (isIncrementalLoadingWorking)
{
return;
}
else
{
isIncrementalLoadingWorking = true;
}
}
var statusBar = StatusBar.GetForCurrentView();
statusBar.ProgressIndicator.Text = ResourceLoader.GetForCurrentView("Resources").GetString("DownloadingMessage");
statusBar.ProgressIndicator.ProgressValue = null;
await statusBar.ProgressIndicator.ShowAsync();
bool isSuccess = await CategoriesSource.LoadMoreItemsAsync(CurrentCategory.Id, CurrentCategory.NextPageUri);
await statusBar.ProgressIndicator.HideAsync();
if (isSuccess)
{
if ((this.DefaultViewModel[Item] as Category).NextPageUri == null)
{
this.Scroll.ViewChanged -= Scroll_ViewChanged;
}
}
else
{
ShowMessageAsync(ResourceLoader.GetForCurrentView("Resources").GetString("ErrorMessage"));
}
lock (IncrementalLoadingHelper)
{
isIncrementalLoadingWorking = false;
}
}
}
}
}
private async void NavigationHelper_LoadState(object sender, LoadStateEventArgs e)
{
this.progressRing.IsActive = true;
Category DisplayedCategory = await CategoriesSource.GetCategoryAsync((string)e.NavigationParameter);
this.progressRing.IsActive = false;
if (DisplayedCategory == null)
{
if (Frame.CanGoBack)
{
Frame.GoBack();
}
else
{
if (!Frame.Navigate(typeof(MainPage), "FoodLook 2"))
{
throw new Exception();
}
Frame.BackStack.Clear();
}
ShowMessageAsync(ResourceLoader.GetForCurrentView("Resources").GetString("ErrorMessage"));
}
else
{
this.DefaultViewModel[Item] = DisplayedCategory;
this.DefaultViewModel[Label] = DisplayedCategory.Label;
if (DisplayedCategory.NextPageUri == null)
{
this.Scroll.ViewChanged -= Scroll_ViewChanged;
}
this.CategoryPagePivot.Visibility = Visibility.Visible;
}
}