using System.Collections.ObjectModel; using CommunityToolkit.Mvvm.ComponentModel; using CommunityToolkit.Mvvm.Input; namespace WpfSample.ViewModels { internal partial class DemoGroupViewModel: ObservableObject { public DemoGroupViewModel() { Random random = new Random(); for (int i = random.Next(1, 10); i >= 0; --i) { Items.Add(new DemoItemViewModel() { Name = $"I{i}", Value = $"V{random.Next()}", }); } Index = random.Next(1, 109); } [ObservableProperty] private string name = string.Empty; public ObservableCollection Items { get; } = new ObservableCollection(); public int Index { get; } [RelayCommand] private void AddItem() { Random random = new Random(); Items.Add(new DemoItemViewModel() { Name = $"I{random.Next()}", Value = $"V{random.Next()}", }); } } }