private void ScrollViewer_ViewChanged(object sender, ScrollViewerViewChangedEventArgs e)
{
if (scrollViewer.VerticalOffset >= scrollViewer.ScrollableHeight - LoadMoreBottomOffset && CanLoadMore)
{
LoadMoreCommand?.Execute(null);
}
}
public HomePageViewModel(INavigationService navigationService, IItemListService itemListService, IEventAggregator eventAggregator) : base(navigationService)
{
_itemListService = itemListService;
_eventAggregator = eventAggregator;
Title = "ホーム";
Items = _itemListService.Items.ToReadOnlyReactiveCollection(i => new ItemViewModel(i)).AddTo(_disposables);
LoadMoreCommand.Subscribe(async item =>
{
if (item == Items?.LastOrDefault())
{
await _itemListService.LoadAsync();
}
});
GoToContributionPageCommand.Subscribe(async() => await NavigateAsync <ContributionPageViewModel>());
GoToItemDetailPageCommand.Subscribe(async viewModel => await NavigateAsync <ItemDetailPageViewModel, string>(viewModel.Id.Value));
_eventAggregator.GetEvent <DestoryEvent>().Subscribe(_itemListService.Close)
.AddTo(_disposables);
_itemListService.LoadAsync();
}
public MyPageViewModel(INavigationService navigationService, IUserItemListService userItemListService, IAccountService accountService, IEventAggregator eventAggregator) : base(navigationService)
{
_userItemListService = userItemListService;
_accountService = accountService;
_eventAggregator = eventAggregator;
Title = "マイページ";
_userItemListService.SetUserId(_accountService.UserId.Value);
Items = _userItemListService.Items.ToReadOnlyReactiveCollection(i => new ItemViewModel(i)).AddTo(_disposables);
UserName = _accountService.UserName;
UserImage = _accountService.UserImage;
ContributionCount = _accountService.ContributionCount;
LoadMoreCommand.Subscribe(async item =>
{
if (item == Items?.LastOrDefault())
{
await _userItemListService.LoadAsync();
}
});
GoToItemDetailPageCommand.Subscribe(async viewModel => await NavigateAsync <ItemDetailPageViewModel, string>(viewModel.Id.Value));
_eventAggregator.GetEvent <DestoryEvent>().Subscribe(_userItemListService.Close)
.AddTo(_disposables);
_userItemListService.LoadAsync();
}
private void MyAdaptiveGridView_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
Debug.WriteLine("内容变更");
if (scrollViewer.ScrollableHeight == 0)
{
LoadMoreCommand?.Execute(null);
}
}
public override void WillDisplay(UITableView tableView, UITableViewCell cell, NSIndexPath indexPath)
{
if ((indexPath.Row >= (ItemsSource.Count() - FromBottomCellStartLoadingIndex)) &&
LoadMoreCommand != null && LoadMoreCommand.CanExecute(null))
{
LoadMoreCommand.Execute(null);
}
}
private void OnItemAppearing(object sender, ItemVisibilityEventArgs e)
{
if (ItemAppearingCommand != null)
{
ItemAppearingCommand?.Execute(e.Item);
}
if (LoadMoreCommand != null)
{
if (IsGroupingEnabled)
{
if (PageSize == null)
{
var firstItem = ((IList)ItemsSource.Cast <object>().First()).Cast <object>().First();
if (e.Item == firstItem && !IsRefreshing)
{
LoadMoreCommand?.Execute(null);
}
}
else
{
var firstItem = ((IList)ItemsSource.Cast <object>().First()).Cast <object>().First();
var totalItems = 0;
foreach (var item in ItemsSource.Cast <object>())
{
totalItems = totalItems + ((IList)item).Cast <object>().Count();
}
if (e.Item == firstItem && !IsRefreshing
& totalItems >= PageSize.Value)
{
LoadMoreCommand?.Execute(null);
}
}
}
else
{
if (PageSize == null)
{
if (e.Item == ItemsSource.Cast <object>().First() && !IsRefreshing)
{
LoadMoreCommand?.Execute(null);
}
}
else
{
if (e.Item == ItemsSource.Cast <object>().First() && !IsRefreshing
& ItemsSource.Cast <object>().Count() >= PageSize.Value)
{
LoadMoreCommand?.Execute(null);
}
}
}
}
}
// If the new item that is appearing on the screen is the last one in the
// collection, we execute the LoadMoreCommand so our ViewModel knows we
// want to load more data for our user from the data service.
private void OnItemAppearing(object sender, ItemVisibilityEventArgs e)
{
ItemAppearingCommand?.Execute(e.Item);
//If its the last item execute command and load more data.
if (e.Item == ItemsSource.Cast <object>().Last())
{
LoadMoreCommand?.Execute(null);
}
}
protected override async Task LoadMoreContent()
{
await Task.Run(async() =>
{
var dataSource = await VmService.LoadReviews(LOADING_REVIEWS_COUNT, Reviews.Count);
CanLoadMore = !dataSource.IsNullOrEmpty() && dataSource.Count == LOADING_REVIEWS_COUNT;
LoadMoreCommand.RaiseCanExecuteChanged();
InvokeOnMainThread(() => Reviews.AddRange(dataSource));
});
}
public override void ExecuteRefreshCommand()
{
if (IsBusy)
{
return;
}
groups.Clear();
OnPropertyChanged("Groups");
CanLoadMore = true;
LoadMoreCommand.Execute(null);
}
void InfiniteListView_ItemAppearing(object sender, ItemVisibilityEventArgs e)
{
var items = AssociatedObject.ItemsSource as IList;
if (items != null && e.Item == items[items.Count - 1])
{
if (LoadMoreCommand != null && LoadMoreCommand.CanExecute(null))
{
LoadMoreCommand.Execute(null);
}
}
}
protected override async Task LoadContent()
{
Loading = true;
Items = await VmService.LoadPoints(SearchText, 0, LOADING_COUNT);
CanLoadMore = !Items.IsNullOrEmpty() && Items.Count >= LOADING_COUNT;
LoadMoreCommand.RaiseCanExecuteChanged();
Loading = false;
}
private void InfiniteListViewItemAppearing(object sender, ItemVisibilityEventArgs e)
{
var items = ItemsSource as IList;
if ((items != null) && (items.Count >= ItemsPerPage) && (items.Count - 3 >= 0) &&
(e.Item == items[items.Count - 3]))
{
if ((LoadMoreCommand != null) && LoadMoreCommand.CanExecute(null))
{
LoadMoreCommand.Execute(null);
}
}
}
protected virtual async Task LoadContent()
{
Loading = true;
var dataSource = await VmService.LoadReviews(LOADING_REVIEWS_COUNT);
InvokeOnMainThread(() => Reviews = dataSource);
CanLoadMore = !dataSource.IsNullOrEmpty() && dataSource.Count == LOADING_REVIEWS_COUNT;
LoadMoreCommand.RaiseCanExecuteChanged();
Loading = false;
}
private void LoadMoreListView_ItemAppearing(object sender, ItemVisibilityEventArgs e)
{
if (ItemsSource is IList items && e.Item == items[items.Count - 1])
{
if (CanLoadMore && LoadStatus == LoadMoreStatus.StatusHasData)
{
if (CanLoadMore && (LoadMoreCommand?.CanExecute(null) == true))
{
LoadMoreCommand.Execute(null);
}
}
}
}
protected override Task LoadMoreContent()
{
return(Task.Run(async() =>
{
var moreItems = await VmService.LoadPoints(SearchText, Items?.Count ?? 0, LOADING_COUNT);
InvokeOnMainThread(() => Items.AddRange(moreItems));
CanLoadMore = !moreItems.IsNullOrEmpty() && moreItems.Count == LOADING_COUNT;
LoadMoreCommand.RaiseCanExecuteChanged();
}));
}
private void LoadArticlesPage(FetchArticlesResult articles)
{
var nextPage = Articles.VirtualPage + 1;
if (nextPage != articles.PageNumber)
{
// Already loaded, discarding the result
return;
}
Articles.AddPage(articles.Articles, articles.TotalCount, articles.PageNumber, articles.PageSize);
LoadMoreCommand.ChangeCanExecute();
Raise(nameof(IsEmpty));
}
private void OnItemAppearing(object sender, ItemVisibilityEventArgs e)
{
if (ItemAppearingCommand != null)
{
ItemAppearingCommand?.Execute(e.Item);
}
if (LoadMoreCommand != null)
{
if (e.Item == ItemsSource.Cast <object>().Last())
{
LoadMoreCommand?.Execute(null);
}
}
}
private void OnItemAppearing(object sender, ItemVisibilityEventArgs e)
{
if (ItemsSource != null && e.Item != null)
{
var items = ItemsSource as IList;
if (e.Item == items[items.Count - 1])
{
var execute = LoadMoreCommand?.CanExecute(e);
if (execute.HasValue && execute.Value)
LoadMoreCommand?.Execute(e.Item);
}
}
}
void LoadMoreListView_ItemAppearing(object sender, ItemVisibilityEventArgs e)
{
var items = ItemsSource as IList;
if (items != null && e.Item == items[items.Count - 1])
{
if (CanLoadMore && LoadStatus == LoadMoreStatus.StausDefault)
{
if (CanLoadMore && (LoadMoreCommand != null && LoadMoreCommand.CanExecute(null)))
{
LoadMoreCommand.Execute(null);
}
}
}
}
private void InfiniteListView_ItemAppearing(object sender, ItemVisibilityEventArgs e)
{
if (IsLoadingMore)
{
return;
}
if (ItemsSource is IList items && e.Item == items[items.Count - 1])
{
if (LoadMoreCommand != null && LoadMoreCommand.CanExecute(null))
{
LoadMoreCommand.Execute(null);
}
}
}
protected override void OnApplyTemplate()
{
scrollViewer = GetTemplateChild("ScrollViewer") as ScrollViewer;
scrollViewer.ViewChanged += ScrollViewer_ViewChanged;
this.RegisterPropertyChangedCallback(LoadingProperty, new DependencyPropertyChangedCallback((obj, e) => {
if (!Loading)
{
if (scrollViewer.ScrollableHeight == 0)
{
LoadMoreCommand?.Execute(null);
}
}
}));
base.OnApplyTemplate();
}
protected override async Task LoadItems()
{
Loading = true;
var dataSource = await VmService.LoadMarkedProducts(LOADING_PRODUCTS_COUNT);
InvokeOnMainThread(() =>
{
Items = dataSource;
Empty = Items.IsNullOrEmpty();
});
CanLoadMore = !dataSource.IsNullOrEmpty() && dataSource.Count == LOADING_PRODUCTS_COUNT;
LoadMoreCommand.RaiseCanExecuteChanged();
Loading = false;
}
void InfiniteListView_ItemAppearing(object sender, ItemVisibilityEventArgs e)
{
byte visibleLoad = 1;
var items = AssociatedObject.ItemsSource as IList;
if ((items == null) || (items?.Count ?? 0) < visibleLoad || (e?.Item ?? null) == null)
{
return;
}
if (items.IndexOf(e?.Item ?? null) >= items.Count - (visibleLoad + 1))
{
if (LoadMoreCommand != null && LoadMoreCommand.CanExecute(null))
{
LoadMoreCommand.Execute(null);
}
}
}
private void ExtendedListView_ItemAppearing(object sender, ItemVisibilityEventArgs e)
{
try
{
if (ItemsSource is IList items && e.Item.Equals(items[items.Count - LoadPositionOffset]))
{
var param = LoadMoreCommandParameter ?? e.Item;
if (LoadMoreCommand != null && LoadMoreCommand.CanExecute(param))
{
LoadMoreCommand.Execute(param);
}
}
}
catch (Exception ex)
{
Debug.WriteLine(ex.Message);
}
}
private void OnItemAppearing(object sender, ItemVisibilityEventArgs e)
{
var items = ItemsSource as IList;
if (_isLoadingMore || items == null || items.Count == 0 || LoadMoreCommand == null || !LoadMoreCommand.CanExecute(e.Item))
{
return;
}
// Hit the bottom
if (e.Item == items[items.Count - 1])
{
_isLoadingMore = true;
LoadMoreCommand.Execute(null);
_isLoadingMore = false;
}
}
void InfiniteListView_ItemAppearing(object sender, ItemVisibilityEventArgs e)
{
try
{
var items = ItemsSource as IList;
if (items.Count > 0)
{
if (items != null && e.Item == items[items.Count - 1])
{
if (LoadMoreCommand != null && LoadMoreCommand.CanExecute(null))
{
LoadMoreCommand.Execute(null);
}
}
}
}
catch (System.Exception ex)
{
}
}
private void InfiniteListView_ItemAppearing(object sender, ItemVisibilityEventArgs e)
{
var items = ItemsSource as IList;
if (items == null)
{
Log.Warn("ItemsSource needs to be of type IList, otherwise performance suffers to great");
return;
}
if (LoadMoreCommand == default(ICommand))
{
return;
}
if (e.Item == items[items.Count - LoadMoreOffset] && LoadMoreCommand.CanExecute(e.Item))
{
LoadMoreCommand.Execute(e.Item);
}
}
protected override async Task LoadMoreContent()
{
if (Loading || LoadingMore)
{
return;
}
LoadingMore = true;
var dataSource = await VmService.LoadHistoryOrders(LOADING_ORDERS_COUNT, offset : Orders.Count);
CanLoadMore = !dataSource.IsNullOrEmpty() && dataSource.Count == LOADING_ORDERS_COUNT;
LoadMoreCommand.RaiseCanExecuteChanged();
InvokeOnMainThread(() =>
{
Orders.AddRange(dataSource);
});
LoadingMore = false;
}
protected override void OnLoadMoreExecute()
{
if (Loading || LoadingMore)
return;
Task.Run(async () =>
{
LoadingMore = true;
var dataSource = await VmService.LoadMarkedProducts(LOADING_PRODUCTS_COUNT, Items.Count);
CanLoadMore = !dataSource.IsNullOrEmpty() && dataSource.Count == LOADING_PRODUCTS_COUNT;
LoadMoreCommand.RaiseCanExecuteChanged();
InvokeOnMainThread(() =>
{
Items.AddRange(dataSource);
Empty = Items.IsNullOrEmpty();
});
LoadingMore = false;
});
}
public LoadMoreListView()
{
ItemAppearing += (sender, args) =>
{
IList items = ItemsSource as IList;
if (items?.Count == 0 && LoadMoreCommand == null && !LoadMoreCommand.CanExecute(null))
{
return;
}
if (args.Item == items[items.Count - 1])
{
LoadMoreCommand.Execute(null);
}
};
Footer = new StackLayout
{
Spacing = 0,
Padding = 12,
VerticalOptions = LayoutOptions.CenterAndExpand,
HorizontalOptions = LayoutOptions.FillAndExpand,
BackgroundColor = Color.Transparent,
Children =
{
new ActivityIndicator
{
IsRunning = true,
HeightRequest = 15,
VerticalOptions = LayoutOptions.CenterAndExpand,
HorizontalOptions = LayoutOptions.FillAndExpand,
Color = AppColor.MainAction
}
}
};
}
