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);
}
}
}
}
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);
}
}
}
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);
}
}
}
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);
}
}
}
}
void InfiniteListView_ItemAppearing(object sender, ItemVisibilityEventArgs e)
{
if (!CanLoadMorePages)
{
return;
}
var items = ItemsSource as IList;
if (items != null && e.Item == items[items.Count - 1])
{
if (LoadMoreCommand != null && LoadMoreCommand.CanExecute(null))
{
LoadMoreCommand.Execute(null);
}
}
}
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);
}
}
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);
}
}
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
}
}
};
}
public LoadMoreListView() : base(ListViewCachingStrategy.RecycleElement)
{
Xamarin.Forms.PlatformConfiguration.iOSSpecific.ListView.SetSeparatorStyle(this, Xamarin.Forms.PlatformConfiguration.iOSSpecific.SeparatorStyle.FullWidth);
loadingPage = new StackLayout
{
Orientation = StackOrientation.Horizontal,
HeightRequest = 50,
Children =
{
new StackLayout
{
VerticalOptions = LayoutOptions.CenterAndExpand,
HorizontalOptions = LayoutOptions.CenterAndExpand,
Orientation = StackOrientation.Horizontal,
Children =
{
new ActivityIndicator {
IsRunning = true,
WidthRequest = 20,
HeightRequest = 20,
Color = (Color)Application.Current.Resources["Primary"],
VerticalOptions = LayoutOptions.CenterAndExpand
},
new Label
{
Text = "Loading...",
Style = Application.Current.Resources["SecondaryTextStyle"] as Style,
VerticalOptions = LayoutOptions.CenterAndExpand
}
}
}
}
};
endPage = new StackLayout
{
HeightRequest = 50,
HorizontalOptions = LayoutOptions.CenterAndExpand,
Children =
{
new Label
{
Text = "No more",
Style = Application.Current.Resources["SecondaryTextStyle"] as Style,
VerticalOptions = LayoutOptions.CenterAndExpand
}
}
};
failPage = new StackLayout
{
HeightRequest = FailHeight,
Children =
{
new StackLayout
{
VerticalOptions = LayoutOptions.EndAndExpand,
HorizontalOptions = LayoutOptions.CenterAndExpand,
Children =
{
new Label
{
Text = "It seems that something went wrong.",
Style = Application.Current.Resources["SecondaryTextStyle"] as Style,
HorizontalOptions = LayoutOptions.CenterAndExpand,
},
new Label
{
Text = "Reload",
Style = Application.Current.Resources["SecondaryTextStyle"] as Style,
TextColor = (Color)Application.Current.Resources["Primary"],
HorizontalOptions = LayoutOptions.CenterAndExpand,
}
}
}
}
};
var failGestureRecognizer = new TapGestureRecognizer();
failGestureRecognizer.Tapped += (s, e) =>
{
if (LoadStatus == LoadMoreStatus.StausFail)
{
RefreshCommand.Execute(null);
}
};
failPage.GestureRecognizers.Add(failGestureRecognizer);
nodataPage = new StackLayout
{
HeightRequest = 50,
HorizontalOptions = LayoutOptions.CenterAndExpand,
Children =
{
new Label
{
Text = "No content yet",
Style = Application.Current.Resources["SecondaryTextStyle"] as Style,
VerticalOptions = LayoutOptions.CenterAndExpand
}
}
};
errorPage = new StackLayout
{
HeightRequest = 50,
HorizontalOptions = LayoutOptions.CenterAndExpand,
Children =
{
new Label
{
Text = "Failed to load, click to try again",
Style = Application.Current.Resources["SecondaryTextStyle"] as Style,
VerticalOptions = LayoutOptions.CenterAndExpand
}
}
};
var errorGestureRecognizer = new TapGestureRecognizer();
errorGestureRecognizer.Tapped += (s, e) =>
{
if (LoadStatus == LoadMoreStatus.StausError && LoadMoreCommand != null && LoadMoreCommand.CanExecute(null))
{
LoadMoreCommand.Execute(null);
}
};
errorPage.GestureRecognizers.Add(errorGestureRecognizer);
nologinPage = new StackLayout
{
HeightRequest = FailHeight,
Children =
{
new StackLayout
{
VerticalOptions = LayoutOptions.EndAndExpand,
HorizontalOptions = LayoutOptions.CenterAndExpand,
Children =
{
new Label
{
Text = "Not logged in yet",
Style = Application.Current.Resources["SecondaryTextStyle"] as Style,
HorizontalOptions = LayoutOptions.CenterAndExpand,
},
new Label
{
Text = "Log in now",
Style = Application.Current.Resources["SecondaryTextStyle"] as Style,
TextColor = (Color)Application.Current.Resources["Primary"],
HorizontalOptions = LayoutOptions.CenterAndExpand,
}
}
}
}
};
var nologinGestureRecognizer = new TapGestureRecognizer();
nologinGestureRecognizer.Tapped += (s, e) =>
{
if (LoadStatus == LoadMoreStatus.StausNologin)
{
MessagingService.Current.SendMessage(MessageKeys.NavigateLogin);
}
};
nologinPage.GestureRecognizers.Add(nologinGestureRecognizer);
ItemAppearing += LoadMoreListView_ItemAppearing;
}
public LoadMoreListView() : base(ListViewCachingStrategy.RecycleElement)
{
loadingPage = new StackLayout
{
Orientation = StackOrientation.Horizontal,
HeightRequest = 50,
Children =
{
new StackLayout
{
VerticalOptions = LayoutOptions.CenterAndExpand,
HorizontalOptions = LayoutOptions.CenterAndExpand,
Orientation = StackOrientation.Horizontal,
Children =
{
new ActivityIndicator {
IsRunning = true,
WidthRequest = 20,
HeightRequest = 20,
Color = (Color)Application.Current.Resources["Primary"],
VerticalOptions = LayoutOptions.CenterAndExpand
},
new Label
{
Text = "正在加载中",
Style = Application.Current.Resources["SecondaryTextStyle"] as Style,
VerticalOptions = LayoutOptions.CenterAndExpand
}
}
}
}
};
endPage = new StackLayout
{
HeightRequest = 50,
HorizontalOptions = LayoutOptions.CenterAndExpand,
Children =
{
new Label
{
Text = "没有更多了",
Style = Application.Current.Resources["SecondaryTextStyle"] as Style,
VerticalOptions = LayoutOptions.CenterAndExpand
}
}
};
failPage = new StackLayout
{
HeightRequest = FailHeight,
Children =
{
new StackLayout
{
VerticalOptions = LayoutOptions.EndAndExpand,
HorizontalOptions = LayoutOptions.CenterAndExpand,
Children =
{
new Label
{
Text = "似乎出了点问题",
Style = Application.Current.Resources["SecondaryTextStyle"] as Style,
HorizontalOptions = LayoutOptions.CenterAndExpand,
},
new Label
{
Text = "重新加载",
Style = Application.Current.Resources["SecondaryTextStyle"] as Style,
TextColor = (Color)Application.Current.Resources["Primary"],
HorizontalOptions = LayoutOptions.CenterAndExpand,
}
}
}
}
};
var failGestureRecognizer = new TapGestureRecognizer();
failGestureRecognizer.Tapped += (s, e) =>
{
if (LoadStatus == LoadMoreStatus.StausFail)
{
RefreshCommand.Execute(null);
}
};
failPage.GestureRecognizers.Add(failGestureRecognizer);
nodataPage = new StackLayout
{
HeightRequest = 50,
HorizontalOptions = LayoutOptions.CenterAndExpand,
Children =
{
new Label
{
Text = "还没有内容",
Style = Application.Current.Resources["SecondaryTextStyle"] as Style,
VerticalOptions = LayoutOptions.CenterAndExpand
}
}
};
errorPage = new StackLayout
{
HeightRequest = 50,
HorizontalOptions = LayoutOptions.CenterAndExpand,
Children =
{
new Label
{
Text = "加载失败，点击重试",
Style = Application.Current.Resources["SecondaryTextStyle"] as Style,
VerticalOptions = LayoutOptions.CenterAndExpand
}
}
};
var errorGestureRecognizer = new TapGestureRecognizer();
errorGestureRecognizer.Tapped += (s, e) =>
{
if (LoadStatus == LoadMoreStatus.StausError && LoadMoreCommand != null && LoadMoreCommand.CanExecute(null))
{
LoadMoreCommand.Execute(null);
}
};
errorPage.GestureRecognizers.Add(errorGestureRecognizer);
nologinPage = new StackLayout
{
HeightRequest = FailHeight,
Children =
{
new StackLayout
{
VerticalOptions = LayoutOptions.EndAndExpand,
HorizontalOptions = LayoutOptions.CenterAndExpand,
Children =
{
new Label
{
Text = "还未登录",
Style = Application.Current.Resources["SecondaryTextStyle"] as Style,
HorizontalOptions = LayoutOptions.CenterAndExpand,
},
new Label
{
Text = "马上登录",
Style = Application.Current.Resources["SecondaryTextStyle"] as Style,
TextColor = (Color)Application.Current.Resources["Primary"],
HorizontalOptions = LayoutOptions.CenterAndExpand,
}
}
}
}
};
var nologinGestureRecognizer = new TapGestureRecognizer();
nologinGestureRecognizer.Tapped += (s, e) =>
{
if (LoadStatus == LoadMoreStatus.StausNologin)
{
MessagingService.Current.SendMessage(MessageKeys.NavigateLogin);
}
};
nologinPage.GestureRecognizers.Add(nologinGestureRecognizer);
ItemAppearing += LoadMoreListView_ItemAppearing;
}
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;
}
}