https://github.com/syncfusionexamples/xamarin-listview-loadmore-upwards
This repository contains the sample about how to use load more upwards using Xamarin.Forms ListView
https://github.com/syncfusionexamples/xamarin-listview-loadmore-upwards
listview load-more load-more-data loadmore xamarin-forms
Last synced: 6 months ago
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This repository contains the sample about how to use load more upwards using Xamarin.Forms ListView
- Host: GitHub
- URL: https://github.com/syncfusionexamples/xamarin-listview-loadmore-upwards
- Owner: SyncfusionExamples
- Created: 2019-07-04T09:40:00.000Z (over 6 years ago)
- Default Branch: master
- Last Pushed: 2024-02-15T13:45:13.000Z (over 1 year ago)
- Last Synced: 2025-02-08T20:48:15.303Z (8 months ago)
- Topics: listview, load-more, load-more-data, loadmore, xamarin-forms
- Language: C#
- Homepage:
- Size: 505 KB
- Stars: 0
- Watchers: 1
- Forks: 1
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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README
# How to load more items in upward direction manually using bottom click
SfListView allows you to load more items in upward direction manually using a button clicked event. Show the busy indicator until the items are added into the
collection as like below code example.
```
```
Insert each new item in the zeroth position of the underlying collection which is bound to the SfListView.ItemsSource property. When the collection gets modified,the ScrollViewer scrolls to the top of the list. Using ScrollToRowIndex method scroll back to the previous item index as like below.
```
public partial class MainPage : ContentPage
{
MainPageViewModel ViewModel;
VisualContainer visualContainer;
public MainPage()
{
InitializeComponent();
ViewModel = new MainPageViewModel();
BindingContext = ViewModel;
ViewModel.ListView = this.ListView;
ListView.Loaded += ListView_Loaded;
visualContainer = ListView.GetVisualContainer();
}
private void ListView_Loaded(object sender, Syncfusion.ListView.XForms.ListViewLoadedEventArgs e)
{
(ListView.LayoutManager as LinearLayout).ScrollToRowIndex(ViewModel.Messages.Count - 1, true);
}
private async void Button_Clicked(object sender, EventArgs e)
{
//To get the current first item which is visible in the View.
var firstItem = ListView.DataSource.DisplayItems[0];
ViewModel.GridIsVisible = false;
ViewModel.IndicatorIsVisible = true;
await Task.Delay(2000);
var r = new Random();
//To avoid layout calls for arranging each and every items to be added in the View.
ListView.DataSource.BeginInit();
for (int i = 0; i < 5; i++)
{
var collection = new Message();
collection.Text = ViewModel.MessageText[r.Next(0, ViewModel.MessageText.Count() - 1)];
collection.IsIncoming = i % 2 == 0 ? true : false;
collection.MessagDateTime = DateTime.Now.ToString();
ViewModel.Messages.Insert(0, collection);
}
ListView.DataSource.EndInit();
var firstItemIndex = ListView.DataSource.DisplayItems.IndexOf(firstItem);
var header = (ListView.HeaderTemplate != null && !ListView.IsStickyHeader) ? 1 : 0;
var totalItems = firstItemIndex + header; //Need to scroll back to previous position else the ScrollViewer moves to top of the list.
ListView.LayoutManager.ScrollToRowIndex(totalItems, true);
ViewModel.GridIsVisible = true;
ViewModel.IndicatorIsVisible = false;
}
}
```
To know more about LoadMore in SfListView, please refer our documentation [here](https://help.syncfusion.com/xamarin/sflistview/loadmore)