OutWit.Common.MVVM 2.0.2

OutWit.Common.MVVM

Cross-platform MVVM library providing base components for building modern .NET applications with WPF, Avalonia, and Blazor.

Features

• Cross-Platform ViewModelBase: Base class for view models with INotifyPropertyChanged support
• Command Implementations:
  • RelayCommand: Simple command with manual CanExecuteChanged raising
  • DelegateCommand<T>: Generic typed command
• Collections:
  • SortedCollection<TKey, TValue>: Sorted collection with change notifications
  • ObservableSortedCollection<TKey, TValue>: Sorted collection observing item property changes
  • SafeObservableCollection<T>: Thread-safe observable collection
• Table Models: Data models for table views (TableView, TableViewPage, TableViewRow, etc.)
• Abstractions: IDispatcher for cross-platform thread marshalling

Installation

dotnet add package OutWit.Common.MVVM

For platform-specific features:

# WPF
dotnet add package OutWit.Common.MVVM.WPF

# Avalonia
dotnet add package OutWit.Common.MVVM.Avalonia

# Blazor
dotnet add package OutWit.Common.MVVM.Blazor

Quick Start

ViewModelBase

public class MyViewModel : ViewModelBase<IApplicationViewModel>
{
    private string m_name = "";

    public MyViewModel(IApplicationViewModel appVm) : base(appVm)
    {
    }

    public string Name
    {
        get => m_name;
        set
        {
            m_name = value;
            OnPropertyChanged();
        }
    }
}

RelayCommand

public class MyViewModel : ViewModelBase<IApplicationViewModel>
{
    public RelayCommand SaveCommand { get; }

    public MyViewModel(IApplicationViewModel appVm) : base(appVm)
    {
        SaveCommand = new RelayCommand(
            execute: _ => Save(),
            canExecute: _ => CanSave());
    }

    private void Save() { /* Save logic */ }
    
    private bool CanSave() => !string.IsNullOrEmpty(Name);

    private void OnNameChanged()
    {
        SaveCommand.RaiseCanExecuteChanged();
    }
}

DelegateCommand<T>

public DelegateCommand<string> SearchCommand { get; }

SearchCommand = new DelegateCommand<string>(
    execute: searchText => PerformSearch(searchText),
    canExecute: searchText => !string.IsNullOrEmpty(searchText));

SortedCollection

Thread-safe sorted collection with change notifications:

var items = new SortedCollection<int, Item>(x => x.Id);

items.ItemsAdded += (s, added) => Console.WriteLine($"Added {added.Count} items");
items.ItemsRemoved += (s, removed) => Console.WriteLine($"Removed {removed.Count} items");

items.Add(new Item { Id = 1, Name = "First" });

ObservableSortedCollection

Observes property changes in collection items:

var items = new ObservableSortedCollection<int, Item>(x => x.Id);

// Listen for item property changes
items.CollectionContentChanged += (sender, e) => 
{
    var item = sender as Item;
    Console.WriteLine($"Property {e.PropertyName} changed on item {item?.Id}");
};

items.Add(new Item { Id = 1, Name = "First" });
items[1].Name = "Updated"; // Triggers CollectionContentChanged

SafeObservableCollection with IDispatcher

// Thread-safe collection that marshals notifications to UI thread
var items = new SafeObservableCollection<Item>(dispatcher);

// Safe to call from background thread
await Task.Run(() => 
{
    foreach (var item in loadedItems)
    {
        items.Add(item); // UI updates happen on correct thread
    }
});

Platform-Specific Packages

Migration from v1.x

See the Migration Guide for detailed instructions.

Key changes:

• Split into cross-platform base and platform-specific packages
• New source generator-based property system
• BindableAttribute is obsolete (use StyledPropertyAttribute)
• SortedCollectionEx renamed to ObservableSortedCollection

Related Packages

• OutWit.Common.MVVM.WPF - WPF-specific implementation
• OutWit.Common.MVVM.Avalonia - Avalonia-specific implementation
• OutWit.Common.MVVM.Blazor - Blazor-specific implementation

License

Licensed under the Apache License, Version 2.0. See LICENSE.

Attribution (optional)

If you use OutWit.Common.MVVM in a product, a mention is appreciated (but not required), for example: "Powered by OutWit.Common.MVVM (https://ratner.io/)".

Trademark / Project name

"OutWit" and the OutWit logo are used to identify the official project by Dmitry Ratner.

You may:

• refer to the project name in a factual way (e.g., "built with OutWit.Common.MVVM");
• use the name to indicate compatibility (e.g., "OutWit.Common.MVVM-compatible").

You may not:

• use "OutWit.Common.MVVM" as the name of a fork or a derived product in a way that implies it is the official project;
• use the OutWit.Common.MVVM logo to promote forks or derived products without permission.