### Setup VirtualListView in MAUI App Builder

Source: https://github.com/redth/maui.virtuallistview/blob/main/README.md

Demonstrates how to enable the VirtualListView control in a .NET MAUI application by adding the '.UseVirtualListView()' extension method to the MauiAppBuilder.

```csharp
public static MauiApp Create()
{
	var builder = MauiApp.CreateBuilder();
	builder
		.UseMauiApp<App>()
		.UseVirtualListView(); // <--- THIS
	return builder.Build();
}
```

--------------------------------

### VirtualListViewAdapter with String List

Source: https://github.com/redth/maui.virtuallistview/blob/main/README.md

An example of creating a basic VirtualListViewAdapter using an array of strings as the data source. This adapter is suitable for simple lists where the data is directly available.

```csharp
var adapter = new VirtualListViewAdapter<string>(
	new [] {
		"Item 1",
		"Item 2",
		"Item 3",
		//...
	});
```

--------------------------------

### Custom Item Data Template Selector

Source: https://github.com/redth/maui.virtuallistview/blob/main/README.md

Example of a custom item template selector that chooses DataTemplates based on the item type (e.g., Person vs. generic).

```csharp
public class MyItemTemplateSelector
{
	PersonTemplate personTemplate = new PersonTemplate();
	GenericTemplate genericTemplate = new GenericTemplate();

	public override DataTemplate SelectItemTemplate(IVirtualListViewAdapter adapter, int sectionIndex, int itemIndex)
	{
		var item = adapter.GetItem(sectionIndex, itemIndex);

		if (item is Person)
			return personTemplate;
		
		return genericTemplate;
	}
}
```

--------------------------------

### VirtualViewCell Template Example (XAML)

Source: https://github.com/redth/maui.virtuallistview/blob/main/README.md

Defines a reusable cell template using VirtualViewCell in XAML. It demonstrates how to bind properties like IsSelected for conditional styling and display item data. Dependencies include the VirtualListView assembly and Xamarin.Forms namespaces.

```xml
<?xml version="1.0" encoding="UTF-8"?>
<xct:VirtualViewCell
	xmlns:xct="clr-namespace:Microsoft.Maui.Controls;assembly=VirtualListView"
	xmlns="http://xamarin.com/schemas/2014/forms" 
	xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
	x:Class="VirtualListViewSample.GenericViewCell">
  <xct:VirtualViewCell>
		<VerticalStackLayout
			Spacing="0"
			BackgroundColor="{Binding Source={x:Reference self}, Path=IsSelected, Converter={StaticResource selectedColorConverter}}">

			<BoxView
				HorizontalOptions="FillAndExpand"
				HeightRequest="1"
				BackgroundColor="#f8f8f8"
				IsVisible="{DynamicResource IsNotFirstItemInSection}" 
 				/>

			<Border Background="#f0f0f0" StrokeShape="{RoundedRectangle CornerRadius=14}" Margin="10,5,10,5" Padding="10">
				<Label Text="{Binding TrackName}" />
			</Border>

		</VerticalStackLayout>
	</xct:VirtualViewCell>
</xct:VirtualViewCell>

```

--------------------------------

### Custom SQLite Adapter for Sectioned List

Source: https://github.com/redth/maui.virtuallistview/blob/main/README.md

Implements IVirtualListViewAdapter for a sectioned list using SQLite. Caches section and item counts, and demonstrates data retrieval for sections and items.

```csharp
public class SQLiteSectionedAdapter : VirtualListViewAdapterBase<GroupInfo, ItemInfo>
{
	public SQLiteSectionedAdapter() : base()
	{
		Db = new Database(...);
	}

	public Database Db { get; }

	Dictionary<int, GroupInfo> cachedSectionSummaries = new ();

	int? cachedNumberOfSections = null;

	public int GetNumberOfSections()
		=> cachedNumberOfSections ??= Db.ExecuteScalar<int>("SELECT DISTINCT COUNT(GroupId) FROM Items");

	// No sections/grouping, so disregard the sectionIndex
	public override int GetNumberOfItemsInSection(int sectionIndex)
		=> cachedItemCount ??= Db.ExecuteScalar<int>("SELECT COUNT(Id) FROM Items");

	public GroupInfo GetSection(int sectionIndex)
	{
		if (cachedSectionSummaries.ContainsKey(sectionIndex))
			return cachedSectionSummaries[sectionIndex];

		var sql = @"
				SELECT DISTINCT g.GroupId, g.GroupName, Count(i.Id) as ItemCount
				FROM Items g
					INNER JOIN Items i ON i.GroupId = g.GroupId
				GROUP BY g.GroupId
				ORDER BY g.GroupName
				LIMIT 1 OFFSET ?
		";

		var groupInfo = Db.FindWithQuery<GroupInfo>(sql, sectionIndex);

		if (groupInfo != null)
			cachedSectionSummaries.Add(sectionIndex, groupInfo);

		return groupInfo;
	}

	public override string GetItem(int sectionIndex, int itemIndex)
		=> Db.FindWithQuery<ItemInfo>("SELECT * FROM Items WHERE GroupId=? ORDER BY Id LIMIT 1 OFFSET ?", sectionIndex, itemIndex);

	public override void InvalidateData()
	{
		// Clear our caches
		// Also do this any time we may insert or delete data 
		cachedItemCount = null;
		cachedNumberOfSections.Clear();

		base.InvalidateData();
	}
}
```

--------------------------------

### Custom SQLite Adapter for Flat List

Source: https://github.com/redth/maui.virtuallistview/blob/main/README.md

Implements IVirtualListViewAdapter for a flat list using SQLite. Caches item counts and demonstrates data invalidation.

```csharp
public class SQLiteAdapter : VirtualListViewAdapterBase<object, ItemInfo>
{
	public SQLiteAdapter() : base()
	{
		Db = new Database(...);
	}

	public Database Db { get; }

	int? cachedItemCount = null;

	// No sections/grouping, so disregard the sectionIndex
	public override int GetNumberOfItemsInSection(int sectionIndex)
		=> cachedItemCount ??= Db.ExecuteScalar<int>("SELECT COUNT(Id) FROM Items");

	public override string GetItem(int sectionIndex, int itemIndex)
		=> Db.FindWithQuery<ItemInfo>("SELECT * FROM Items ORDER BY Id LIMIT 1 OFFSET ?", itemIndex);

	public override void InvalidateData()
	{
		// Clear our item count cache
		// Also do this any time we may insert or delete data 
		cachedItemCount = null;
		base.InvalidateData();
	}
}
```

--------------------------------

### IVirtualListViewAdapter Interface

Source: https://github.com/redth/maui.virtuallistview/blob/main/README.md

Defines the contract for data sources used by VirtualListView. It includes methods for retrieving section and item counts, accessing items, and managing data invalidation events.

```csharp
public interface IVirtualListViewAdapter
{
	int GetNumberOfSections();
	object GetSection(int sectionIndex);
	int GetNumberOfItemsInSection(int sectionIndex);
	object GetItem(int sectionIndex, int itemIndex);
	event EventHandler OnDataInvalidated;
	void InvalidateData();
}
```

--------------------------------

### ObservableCollectionAdapter for ObservableCollection

Source: https://github.com/redth/maui.virtuallistview/blob/main/README.md

Shows how to use the ObservableCollectionAdapter to bridge a .NET ObservableCollection to the VirtualListView's adapter pattern. It automatically handles data invalidation when the collection changes.

```csharp
var items = new ObservableCollection<string>();
items.Add("Item 1");
items.Add("Item 2");

var adapter = new ObservableCollectionAdapter<string>(items);

items.Add("Item 3");
```

--------------------------------

### Empty View Configuration (XAML)

Source: https://github.com/redth/maui.virtuallistview/blob/main/README.md

Configures a custom Grid with a Label to be displayed when the VirtualListView contains no items. This provides user feedback for an empty data state.

```xml
<vlv:VirtualListView.EmptyView>
  <Grid>
    <Label HorizontalOptions="Center" VerticalOptions="Center" Text="EMPTY" />
  </Grid>
</vlv:VirtualListView.EmptyView>

```

=== COMPLETE CONTENT === This response contains all available snippets from this library. No additional content exists. Do not make further requests.