Avalonia Collectionview

6.7 CollectionView를 사용한 MVVM 패턴

⚠️ 중요: AvaloniaUI는 WPF의 CollectionViewSource를 지원하지 않습니다.

프로젝트 구조

templates 폴더에 .NET 9 AvaloniaUI 프로젝트 예제가 포함되어 있습니다.

templates/
├── AvaloniaCollectionViewSample.Core/           ← 순수 C# 모델 및 인터페이스
│   ├── Member.cs
│   ├── IMemberCollectionService.cs
│   └── AvaloniaCollectionViewSample.Core.csproj
├── AvaloniaCollectionViewSample.ViewModels/     ← ViewModel (Avalonia 참조 없음)
│   ├── MainViewModel.cs
│   ├── GlobalUsings.cs
│   └── AvaloniaCollectionViewSample.ViewModels.csproj
├── AvaloniaCollectionViewSample.AvaloniaServices/ ← Avalonia Service Layer
│   ├── MemberCollectionService.cs
│   ├── GlobalUsings.cs
│   └── AvaloniaCollectionViewSample.AvaloniaServices.csproj
└── AvaloniaCollectionViewSample.App/            ← Avalonia Application
    ├── Views/
    │   ├── MainWindow.axaml
    │   └── MainWindow.axaml.cs
    ├── App.axaml
    ├── App.axaml.cs
    ├── Program.cs
    ├── GlobalUsings.cs
    └── AvaloniaCollectionViewSample.App.csproj

AvaloniaUI에서는 다음 방법들을 사용:

6.7.1 DataGridCollectionView 사용 (권장)

// NuGet: Avalonia.Controls.DataGrid
// Service Layer
namespace MyApp.Services;

using Avalonia.Controls;

public sealed class MemberCollectionService
{
    private ObservableCollection<Member> Source { get; } = [];

    // DataGridCollectionView 반환
    // Returns DataGridCollectionView
    public IEnumerable CreateView(Predicate<Member>? filter = null)
    {
        var view = new DataGridCollectionView(Source);

        if (filter is not null)
        {
            view.Filter = item => filter((Member)item);
        }

        return view;
    }

    public void Add(Member item) => Source.Add(item);
    public void Remove(Member? item) { if (item is not null) Source.Remove(item); }
    public void Clear() => Source.Clear();
}

6.7.2 ReactiveUI 사용 (대안)

// NuGet: ReactiveUI.Avalonia
namespace MyApp.ViewModels;

using ReactiveUI;
using DynamicData;

public sealed class MainViewModel : ReactiveObject
{
    private readonly SourceList<Member> _sourceList = new();
    private readonly ReadOnlyObservableCollection<Member> _members;

    public ReadOnlyObservableCollection<Member> Members => _members;

    public MainViewModel()
    {
        _sourceList
            .Connect()
            .Filter(m => m.IsActive) // 필터링
                                     // Filtering
            .Sort(SortExpressionComparer<Member>.Ascending(m => m.Name)) // 정렬
                                                                          // Sorting
            .Bind(out _members)
            .Subscribe();
    }

    public void AddMember(Member member) => _sourceList.Add(member);
    public void RemoveMember(Member member) => _sourceList.Remove(member);
}