> For the complete documentation index, see [llms.txt](https://adospace.gitbook.io/mauireactor/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://adospace.gitbook.io/mauireactor/components/controls/collectionview.md).

# CollectionView

> The .NET Multi-platform App UI (.NET MAUI) [CollectionView](https://learn.microsoft.com/en-us/dotnet/api/microsoft.maui.controls.collectionview) is a view for presenting lists of data using different layout specifications. It aims to provide a more flexible, and performant alternative to [ListView](https://learn.microsoft.com/en-us/dotnet/api/microsoft.maui.controls.listview).

Official documentation:\
<https://learn.microsoft.com/en-us/dotnet/maui/user-interface/controls/collectionview/>\
\
MauiReactor sample app:\
<https://github.com/adospace/mauireactor-samples/tree/main/Controls/CollectionViewTestApp>

## Display data

Use the method `ItemsSource()` to link a collection of items and to define how each item is displayed.

{% hint style="info" %}
Bind the CollectionView to an IEnumerable (i.e. List or Array) you do not need to modify the collection (read-only collections). \
If you want to update the list, adding or removing items, use an ObservableCollection instead.
{% endhint %}

For example:&#x20;

```csharp
protected override void OnMounted()
{
    var person1 = new Person("John", "Doe", new DateTime(1980, 5, 10));
    var person2 = new Person("Jane", "Smith", new DateTime(1990, 6, 20));
    var person3 = new Person("Alice", "Johnson", new DateTime(1985, 7, 30));
    var person4 = new Person("Bob", "Williams", new DateTime(2000, 8, 15));
    var person5 = new Person("Charlie", "Brown", new DateTime(1995, 9, 25));

    State.Persons = new [] { person1, person2, person3, person4, person5 };
    base.OnMounted();
}

public override VisualNode Render()
{
    return ContentPage(
        CollectionView()
            .ItemsSource(State.Persons, RenderPerson)
    );
}

private VisualNode RenderPerson(Person person)
{
    return VStack(spacing: 5,
        Label($"{person.FirstName} {person.LastName}"),
        Label(person.DateOfBirth.ToShortDateString())
            .FontSize(12)
            .TextColor(Colors.Gray)
    )
    .Margin(5,10);
}
```

<figure><img src="/files/MBCrgsgadisZgjMa32OB" alt=""><figcaption><p>CollectionView showing some data</p></figcaption></figure>


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://adospace.gitbook.io/mauireactor/components/controls/collectionview.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.