24
votes

I'm having issues with scrolling through ListViews in my Windows Phone 8.1 App. Short lists scroll just fine, scrolling smoothly however as soon Virtualization kicks in the entire ListView "wobbles" to the left slightly, but noticeable enough to be annoying.

I've tried remove all the transitions to no effect as well as having items load incrementally to no success. Setting the item panel to a StackPanel (removing virtualization) fixes the issue but is not preferable.

My listviews are binding to a property in the DefaultViewModel that comes with the Basic Page Template.

What am I doing wrong and what are causing my ListViews to exhibit this behavior?

XAML:

<ListView x:Name="searchResultsList" IsItemClickEnabled="True" ItemClick="ListView_ItemClick" ItemsSource="{Binding searchResults}">
   <ListView.ItemContainerStyle>
      <Style TargetType="ListViewItem">
          <Setter Property="HorizontalContentAlignment" Value="Stretch"/>
          <Setter Property="Margin" Value="0,0,0,20" />
      </Style>
   </ListView.ItemContainerStyle>
   <ListView.ItemTemplate>
      <DataTemplate>
          <Grid>
             <Grid.ColumnDefinitions>
                <ColumnDefinition Width="80" />
                <ColumnDefinition Width="10" />
                <ColumnDefinition Width="*" />
             </Grid.ColumnDefinitions>

             <Border Width="80" Height="80">
                <Image Source="{Binding Image}" />
             </Border>

             <StackPanel Grid.Column="2">
                <TextBlock Text="{Binding PodcastTitle}" TextWrapping="WrapWholeWords" FontSize="{StaticResource TextStyleExtraLargeFontSize}" />
                <TextBlock Text="{Binding LastUpdated, Converter={StaticResource dateConverter}}" Style="{ThemeResource ListViewItemSubheaderTextBlockStyle}" />
                <TextBlock Text="{Binding PodcastArtist}" TextWrapping="WrapWholeWords" Style="{ThemeResource ListViewItemContentTextBlockStyle}" />
             </StackPanel>
           </Grid>
       </DataTemplate>
   </ListView.ItemTemplate>
 </ListView>
5
So "wobbles" was the thing to google for... I couldn't figure out how to describe the phenomenon...!Factor Mystic
@FactorMystic Same here. I didn't know what to look for. I think, that is the reason this issue isn't drawing enough attention.akshay2000

5 Answers

23
votes

So this seems to be an OS issue, as evidenced in this thread on the MS forums: http://social.msdn.microsoft.com/Forums/en-US/9a363d33-5760-4d38-9c81-84259c4edcbe/listview-jiggles-horizontally-when-large-item-about-to-scroll-in-or-out-in-windows-phone-81-preview?forum=WindowsPhonePreviewSDK&prof=required.

The issue does indeed lie in virtualization, with items that have no fixed width. Using star as the width or making the horizontal alignment stretch won't work so the only solution that takes account orientation and resolution was to bind the width to the ListView's container's ActualWidth property:

<Grid x:name="contentRoot" Margin="19,9.5,19,0">
<ListView>
 <ListView.ItemTemplate>
   <DataTemplate>
     <Grid Width={Binding ActualWidth, ElementName=contentRoot} />

   </DataTemplate>

 </ListView.ItemTemplate>
</ListView>
</Grid>
6
votes

The first element in the listview is not displayed because the ActiualWidth of the Grid is 0 in the first second, when loaded the page. This is the solution, that's working for me:

<Grid x:Name="contentRoot" Margin="20">
<ListView>
 <ListView.ItemTemplate>
   <DataTemplate>
     <Grid MinWidth="{Binding ActualWidth, ElementName=contentRoot}" />
   </DataTemplate>
 </ListView.ItemTemplate>
</ListView>
</Grid>
3
votes

This is a really annoying bug. I can't understand why this is not fixed since years now.

Imho stretching items in a vertical scrolling listview is a very basic feature and should work 100%.

A possible workaround is also this snipped, which should also be aware of size changes :

public class StrechItemsListView : ListView
{
    public StrechItemsListView()
    {
        SizeChanged += StrechItemsListView_SizeChanged;
    }

    private void StrechItemsListView_SizeChanged(object sender, SizeChangedEventArgs e)
    {
        if (ItemsPanelRoot != null)
        {
            ItemsPanelRoot.Width = e.NewSize.Width;
        }
    }
}

Changing the xaml only to a custom listview type is less work and cleaner then edit every datatemplate etc. Just my 2 cents.

2
votes

My Practice seems to work. At least in WP8.1.

Just set the ItemsPanelTemplate in the <ListView></ListView> Block explicitly, but not use

Style="{StaticResource ListViewStyle1}" or something else.

Sample Code:

<ListView ItemsSource="{Binding RadioList}" ScrollViewer.HorizontalScrollBarVisibility="Hidden" ScrollViewer.HorizontalScrollMode="Disabled"
            ScrollViewer.VerticalScrollBarVisibility="Hidden" ScrollViewer.VerticalScrollMode="Auto">
        <ListView.ItemTemplate>
            <DataTemplate>
                <Grid Margin="10,3,10,0">
                    <TextBlock Text="{Binding RadioName}" FontSize="15" VerticalAlignment="Center" HorizontalAlignment="Center"/>
                </Grid>
            </DataTemplate>
        </ListView.ItemTemplate>
        <ListView.ItemContainerStyle>
            <Style TargetType="ListViewItem">
                <Setter Property="HorizontalContentAlignment" Value="Stretch"/>
            </Style>
        </ListView.ItemContainerStyle>
        <ListView.ItemsPanel>
            <ItemsPanelTemplate>
                <VirtualizingStackPanel Orientation="Vertical" Width="{Binding PhoneWidth}"/>
            </ItemsPanelTemplate>
        </ListView.ItemsPanel>
    </ListView>

The HorizontalContentAlignment and Width of VirtualizingStackPanel settings are used to center the content in the ListView .You can move these settings freely.I don't know why, but it does work.

0
votes

This was fixed on Windows 10 for Windows 8.1 apps