Avalonia下DataGrid多选MVVM绑定的功能

安装Avalonia.Xaml.Behaviors

Install-Package Avalonia.Xaml.Behaviors

DataGridSelectedItemsBehavior.cs

using Avalonia;
using Avalonia.Controls;
using Avalonia.Threading;
using Avalonia.Xaml.Interactivity;

namespace CgdataBase;

public class DataGridSelectedItemsBehavior : Behavior<DataGrid>
{
    public static readonly DirectProperty<DataGridSelectedItemsBehavior, IList> SelectedItemsProperty =
        AvaloniaProperty.RegisterDirect<DataGridSelectedItemsBehavior, IList>(nameof(SelectedItems),
            o => o.SelectedItems, (o, v) => o.SelectedItems = v);

    private IList _selectedItems;

    public IList SelectedItems
    {
        get => _selectedItems;
        set => SetAndRaise<IList>(SelectedItemsProperty, ref _selectedItems, value as IList);
    }

    protected override void OnAttached()
    {
        base.OnAttached();
        if (AssociatedObject is { })
        {
            AssociatedObject.SelectionChanged += AssociatedObject_SelectionChanged;
        }
    }

    protected override void OnDetaching()
    {
        base.OnDetaching();
        if (AssociatedObject is { })
        {
            AssociatedObject.SelectionChanged -= AssociatedObject_SelectionChanged;
        }
    }

    private void AssociatedObject_SelectionChanged(object sender, SelectionChangedEventArgs e)
    {
        Dispatcher.UIThread.Post(() =>
        {
            SelectedItems = AssociatedObject.SelectedItems;
        });
    }
}

前台代码

增加引用

    xmlns:i="using:Avalonia.Xaml.Interactivity"

绑定：

        <DataGrid
            IsReadOnly="True"
            ItemsSource="{Binding Items}"
            SelectedItem="{Binding SelectedItem}">

            <i:Interaction.Behaviors>
                <cg2:DataGridSelectedItemsBehavior SelectedItems="{Binding SelectedItems, Mode=TwoWay}" />
            </i:Interaction.Behaviors>
        </DataGrid>

后台代码

    [Reactive] public IList SelectedItems { get; set; }

使用：

var items = SelectedItems.Cast<SatelliteInfo>().ToArray();