listview-fast-scrolling.md

title	description	ms.date
ListView fast scrolling on Android	This article explains how to consume the .NET MAUI Android platform-specific that enables fast scrolling through data in a ListView.	04/05/2022

ListView fast scrolling on Android

This .NET Multi-platform App UI (.NET MAUI) Android platform-specific is used to enable fast scrolling through data in a xref:Microsoft.Maui.Controls.ListView. It's consumed in XAML by setting the ListView.IsFastScrollEnabled attached property to a boolean value:

<ContentPage ...
             xmlns:android="clr-namespace:Microsoft.Maui.Controls.PlatformConfiguration.AndroidSpecific;assembly=Microsoft.Maui.Controls">
    <StackLayout>
        ...
        <ListView ItemsSource="{Binding GroupedEmployees}"
                  GroupDisplayBinding="{Binding Key}"
                  IsGroupingEnabled="true"
                  android:ListView.IsFastScrollEnabled="true">
            ...
        </ListView>
    </StackLayout>
</ContentPage>

Alternatively, it can be consumed from C# using the fluent API:

using Microsoft.Maui.Controls.PlatformConfiguration.AndroidSpecific;
...

var listView = new Microsoft.Maui.Controls.ListView { IsGroupingEnabled = true, ... };
listView.SetBinding(ItemsView<Cell>.ItemsSourceProperty, "GroupedEmployees");
listView.GroupDisplayBinding = new Binding("Key");
listView.On<Microsoft.Maui.Controls.PlatformConfiguration.Android>().SetIsFastScrollEnabled(true);

The ListView.On<Microsoft.Maui.Controls.PlatformConfiguration.Android> method specifies that this platform-specific will only run on Android. The ListView.SetIsFastScrollEnabled method, in the Microsoft.Maui.Controls.PlatformConfiguration.AndroidSpecific namespace, is used to enable fast scrolling through data in a xref:Microsoft.Maui.Controls.ListView. In addition, the SetIsFastScrollEnabled method can be used to toggle fast scrolling by calling the IsFastScrollEnabled method to return whether fast scrolling is enabled:

listView.On<Microsoft.Maui.Controls.PlatformConfiguration.Android>().SetIsFastScrollEnabled(!listView.On<Microsoft.Maui.Controls.PlatformConfiguration.Android>().IsFastScrollEnabled());

The result is that fast scrolling through data in a xref:Microsoft.Maui.Controls.ListView can be enabled, which changes the size of the scroll thumb:

:::image type="content" source="media/listview-fast-scrolling/fastscroll.png" alt-text="ListView FastScroll Platform-Specific.":::