# .NET MAUI CollectionView LoadOnDemand Command

The `LoadOnDemandCommand` (of type `ICommand`) is another alternative which you can use for loading data on demand. This alternative is suitable for MVVM scenarios.

## Example

The following example demonstrates a simple setup that shows how to use the command:

**1.** Create a sample model:

```C#
public class Person
{
    public string Name { get; set; }
    public int Age { get; set; }
    public Gender Gender { get; set; }
}
```

**2.** Define the CollectionView control:

```XAML
<telerik:RadCollectionView ItemsSource="{Binding Items}"
                           DisplayMemberPath="Name"
                           IsLoadOnDemandEnabled="True"
                           IsLoadOnDemandActive="{Binding IsLoadOnDemandActive, Mode=TwoWay}"
                           LoadOnDemandCommand="{Binding LoadOnDemandCommand}">
    <telerik:RadCollectionView.BindingContext>
        <local:LoadOnDemandCommandViewModel />
    </telerik:RadCollectionView.BindingContext>
</telerik:RadCollectionView>
```

**3.** Add the `telerik` namespace:

```XAML
xmlns:telerik="http://schemas.telerik.com/2022/xaml/maui"
```

**4.** Create a `ViewModel` and define a command that is bound to the `RadCollectionView.LoadOnDemandCommand` property:

```C#
public class LoadOnDemandCommandViewModel : NotifyPropertyChangedBase
{
    private bool isLoadOnDemandActive;

    public LoadOnDemandCommandViewModel()
    {
        this.Items = new ObservableCollection<Person>();

        for (int i = 0; i < 20; i++)
        {
            this.Items.Add(new Person { Name = "Person " + i, Age = i + 10 });
        }

        this.LoadOnDemandCommand = new Command(async () =>
        {
            this.IsLoadOnDemandActive = true;

            IEnumerable<Person> newItems = await this.GetNewItems();
            foreach (var newItem in newItems)
            {
                this.Items.Add(newItem);
            }

            this.IsLoadOnDemandActive = false;
        });
    }

    public ObservableCollection<Person> Items { get; set; }

    public ICommand LoadOnDemandCommand { get; set; }

    public bool IsLoadOnDemandActive
    {
        get => this.isLoadOnDemandActive;
        set => this.UpdateValue(ref this.isLoadOnDemandActive, value);
    }

    private async Task<IEnumerable<Person>> GetNewItems()
    {
        List<Person> newItems = new List<Person>();
        int count = this.Items.Count;

        try
        {
            await Task.Delay(2000);

            for (int i = 0; i < 10; i++)
            {
                newItems.Add(new Person { Name = $"Loaded item: Person {count + i}", Age = i + 10 });
            }

            return newItems;
        }
        catch (Exception)
        {
            return null;
        }
    }
}
```

This is the result:

![Telerik UI for .NET MAUI CollectionView loading additional Person items on demand using the load on demand command](https://www.telerik.com/maui-ui/documentation/assets/9228e53eed9e4fafef65254d6533a6c5/load-on-demand.gif "Telerik .NET MAUI CollectionView")

> For a runnable example demonstrating the CollectionView LoadOnDemand Command, see the [SDKBrowser Demo Application](https://www.telerik.com/maui-ui/documentation/demos-and-sample-apps/sdkbrowser-app) and go to **CollectionView > Load On Demand** category.

## See Also

* [Load On Demand Collection](https://www.telerik.com/maui-ui/documentation/controls/collectionview/load-on-demand/collection)
* [Load On Demand Event](https://www.telerik.com/maui-ui/documentation/controls/collectionview/load-on-demand/event)
* [Customize the Load On Demand Manual and Automatic Loading Indicators](https://www.telerik.com/maui-ui/documentation/controls/collectionview/load-on-demand/templates)