Scrollviewer ChangeView function not scrolling to bottom - xaml

Question

I have used listview inside scrollviewer in windows phone 8.1 rt app.
I have a requirement of scrolling to bottom of list but change view function is not working as per requirement.
Created a sample for same scenario:
MainPage.xaml
<Page
x:Class="InfiList.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:InfiList"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:customlv="using:InfiList"
mc:Ignorable="d"
Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
<Page.Resources>
<Style x:Key="ListViewStyle1" TargetType="ListView">
<Setter Property="IsTabStop" Value="False"/>
<Setter Property="TabNavigation" Value="Once"/>
<Setter Property="IsSwipeEnabled" Value="True"/>
<Setter Property="HorizontalContentAlignment" Value="Stretch"/>
<Setter Property="VerticalContentAlignment" Value="Top"/>
<Setter Property="ItemContainerTransitions">
<Setter.Value>
<TransitionCollection>
<AddDeleteThemeTransition/>
<ReorderThemeTransition/>
</TransitionCollection>
</Setter.Value>
</Setter>
<Setter Property="ItemsPanel">
<Setter.Value>
<ItemsPanelTemplate>
<ItemsStackPanel Orientation="Vertical"/>
</ItemsPanelTemplate>
</Setter.Value>
</Setter>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="ListView">
<Border BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}">
<ItemsPresenter FooterTransitions="{TemplateBinding FooterTransitions}" FooterTemplate="{TemplateBinding FooterTemplate}" Footer="{TemplateBinding Footer}" HeaderTemplate="{TemplateBinding HeaderTemplate}" Header="{TemplateBinding Header}" HeaderTransitions="{TemplateBinding HeaderTransitions}" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" Padding="{TemplateBinding Padding}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</Page.Resources>
<Grid x:Name="root">
<ScrollViewer x:Name="MyScrollViewer" ViewChanged="OnViewChanged" IsVerticalScrollChainingEnabled="True">
<ListView x:Name="listview" ItemsSource="{Binding Collection}" Style="{StaticResource ListViewStyle1}" >
<ListView.ItemContainerStyle>
<Style TargetType="ListViewItem">
<Setter Property="HorizontalContentAlignment" Value="Stretch"/>
<Setter Property="VerticalContentAlignment" Value="Stretch"/>
</Style>
</ListView.ItemContainerStyle>
<ListView.ItemsPanel>
<ItemsPanelTemplate>
<ItemsStackPanel ItemsUpdatingScrollMode="KeepItemsInView"/>
</ItemsPanelTemplate>
</ListView.ItemsPanel>
<ListView.ItemTemplate>
<DataTemplate>
<Grid Background="LightGray" HorizontalAlignment="Left" Margin="25">
<TextBlock Margin="25 25 25 50" FontSize="32" Text="{Binding}" TextWrapping="WrapWholeWords" MaxWidth="200"/>
</Grid>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</ScrollViewer>
</Grid>
<Page.BottomAppBar>
<CommandBar>
<AppBarButton Click="AppBarButton_Click">
</AppBarButton>
</CommandBar>
</Page.BottomAppBar>
MainPage.xaml.cs
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices.WindowsRuntime;
using Windows.Foundation;
using Windows.Foundation.Collections;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Controls.Primitives;
using Windows.UI.Xaml.Data;
using Windows.UI.Xaml.Input;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Navigation;
// The Blank Page item template is documented at http://go.microsoft.com/fwlink/?LinkId=391641
namespace InfiList
{
/// <summary>
/// An empty page that can be used on its own or navigated to within a Frame.
/// </summary>
public sealed partial class MainPage : Page
{
public ObservableCollection<String> Collection { get; set; }
private bool incall;
private int offset;
int _noofelements;
public MainPage()
{
this.InitializeComponent();
Collection = new ObservableCollection<string>();
listview.DataContext = this;
this.NavigationCacheMode = NavigationCacheMode.Required;
addNumber(0);
listview.Loaded += listview_Loaded;
}
void listview_Loaded(object sender, RoutedEventArgs e)
{
MyScrollViewer.ChangeView(null, int.MaxValue, null, true);
}
private void OnViewChanged(object sender, ScrollViewerViewChangedEventArgs e)
{
ScrollViewer view = (ScrollViewer)sender;
Debug.WriteLine("Vertica Pffset: " + view.VerticalOffset);
if ((view.VerticalOffset < 0.1 * view.ScrollableHeight) & !incall)
{
incall = true;
addNumber(++offset);
}
}
private void addNumber(int offset)
{
int scrollcount = 30;
int start = offset * scrollcount;
for (int i = start; i < start + scrollcount; i++)
{
string s= (_noofelements++).ToString() ;
if (i % 2 == 0)
s += "msdkd kmsdksdk kdsmkd skmcds ckdsmckds ckdsmcksd kcmdskcdsc kdmmcsckdsc" + Environment.NewLine + "sdjndsjnds"
+ "msdkd kmsdksdk kdsmkd skmcds ckdsmckds ckdsmcksd kcmdskcdsc kdmmcsckdsc" + Environment.NewLine + "sdjndsjnds"
+ "dssdsddsds";
Collection.Insert(0,s);
}
incall = false;
}
/// <summary>
/// Scrolls to bottom
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void AppBarButton_Click(object sender, RoutedEventArgs e)
{
MyScrollViewer.ChangeView(null, int.MaxValue, null, true);
//MyScrollViewer.ScrollToVerticalOffset(int.MaxValue);
//For scrolling till top
//MyScrollViewer.ScrollToVerticalOffset(0);
}
}
}
Is there any way to achieve desired functionality?

Answer 1

Use scrollviewer's ExtentHeight
scrollViewer.ChangeView(null, scrollViewer.ExtentHeight, null);
sample: https://github.com/HimanshPal/ListViewVirtualizationTest

Answer 2

I had a similar problem when I used a scroll viewer with the change view. It just never truly reached the bottom. Just by surprise, I found a function that is called UpdateLayout(). I use this function before the change view function and it finally worked.

Answer 3

Try to use ListView.ScrollIntoView,
for example:
listView.ScrollIntoView(listView.Items.Last(), ScrollIntoViewAlignment.Leading);