Ecng.ComponentModel

MVVM infrastructure, property change notifications, validation attributes, and UI component helpers.

Property Change Notifications

NotifiableObject

Base class implementing INotifyPropertyChanged and INotifyPropertyChanging.

using Ecng.ComponentModel; public class Person : NotifiableObject { private string _name; public string Name { get => _name; set { if (_name == value) return; NotifyChanging(); // Fires PropertyChanging _name = value; NotifyChanged(); // Fires PropertyChanged } } } // Subscribe to changes var person = new Person(); person.PropertyChanged += (s, e) => { Console.WriteLine($"{e.PropertyName} changed"); };

ViewModelBase

Extended base class for ViewModels with dispatcher support.

public class MainViewModel : ViewModelBase { private bool _isLoading; public bool IsLoading { get => _isLoading; set { _isLoading = value; NotifyChanged(); } } }

DispatcherNotifiableObject

Notifiable object that marshals property changes to the UI thread.

public class ThreadSafeModel : DispatcherNotifiableObject { // PropertyChanged events automatically dispatched to UI thread }

Observable Collections

ObservableCollectionEx

Extended ObservableCollection<T> with additional features.

var collection = new ObservableCollectionEx<Item>(); // Add range (fires single notification) collection.AddRange(items); // Remove range collection.RemoveRange(itemsToRemove); // Reset with new items collection.Reset(newItems);

DispatcherObservableCollection

Thread-safe observable collection with UI dispatcher support.

var collection = new DispatcherObservableCollection<Item>(); // Safe to modify from any thread Task.Run(() => { collection.Add(new Item()); // Automatically dispatched });

ConvertibleObservableCollection

Observable collection that transforms source items.

var models = new ObservableCollection<PersonModel>(); var viewModels = new ConvertibleObservableCollection<PersonModel, PersonViewModel>( models, model => new PersonViewModel(model)); // Adding to models automatically adds to viewModels models.Add(new PersonModel());

Range Types

Range

Generic range with min/max bounds.

var range = new Range<int>(1, 100); // Check containment bool contains = range.Contains(50); // true bool outside = range.Contains(150); // false // Range properties int min = range.Min; // 1 int max = range.Max; // 100 int length = range.Length; // 99 // Range operations var other = new Range<int>(50, 150); var intersection = range.Intersect(other); // Range(50, 100) var subRange = range.SubRange(20, 80); // Range(20, 80)

NumericRange

Specialized numeric range with additional operations.

var range = new NumericRange<decimal>(0, 100); // Percentage calculations, clamping, etc.

Validation Attributes

Numeric Validation

public class Settings { [IntValidation(Min = 1, Max = 100)] public int Count { get; set; } [DoubleValidation(Min = 0.0, Max = 1.0)] public double Factor { get; set; } [DecimalValidation(Min = 0)] public decimal Price { get; set; } [LongValidation(Min = 0, Max = 1000000)] public long Volume { get; set; } }

TimeSpan Validation

[TimeSpanValidation(Min = "00:00:01", Max = "24:00:00")] public TimeSpan Timeout { get; set; }

Price Validation

[PriceValidation(Min = 0)] public Price StockPrice { get; set; }

Price Type

Financial price with type information.

var price = new Price(100.50m, PriceTypes.Limit); // Price types PriceTypes.Limit // Limit price PriceTypes.Market // Market price PriceTypes.Percent // Percentage

Attributes

Step Attribute

Define increment step for numeric properties.

[Step(0.01)] public decimal Price { get; set; } [Step(1)] public int Quantity { get; set; }

Icon Attributes

[Icon("path/to/icon.png")] public class MyCommand { } [VectorIcon("fas fa-home")] // Font Awesome style public class HomeCommand { }

Doc Attribute

Link to documentation.

[Doc("https://docs.example.com/my-feature")] public class MyFeature { }

BasicSetting Attribute

Mark property as a basic (commonly used) setting.

[BasicSetting] public string ApiKey { get; set; }

Server Credentials

Manage server connection credentials securely.

var credentials = new ServerCredentials { Email = "user@example.com", Password = "secret".Secure(), // SecureString Token = "api-token".Secure() }; // Check if configured bool isConfigured = credentials.IsConfigured;

Process Singleton

Ensure only one instance of an application runs.

using var singleton = new ProcessSingleton("MyApp"); if (!singleton.TryAcquire()) { Console.WriteLine("Another instance is already running"); return; } // Application continues...

Dispatcher

Abstract UI thread dispatcher.

public interface IDispatcher { void Invoke(Action action); Task InvokeAsync(Action action); void BeginInvoke(Action action); } // Check if on UI thread if (!dispatcher.CheckAccess()) { dispatcher.Invoke(() => UpdateUI()); }

Channel Executor

Process items from a channel with controlled concurrency.

var executor = new ChannelExecutor<WorkItem>( processItem: async item => { await ProcessAsync(item); }, maxConcurrency: 4); // Add work executor.Enqueue(new WorkItem()); // Graceful shutdown await executor.StopAsync();

Statistics

Track simple statistics.

var stat = new Stat("ProcessedItems"); stat.Increment(); stat.Add(5); Console.WriteLine($"Total: {stat.Value}");

Periodic Action Planner

Schedule recurring actions.

var planner = new PeriodicActionPlanner(); planner.Schedule( TimeSpan.FromMinutes(5), async () => await RefreshDataAsync()); // Stop scheduling planner.Cancel();

NuGet

Install-Package Ecng.ComponentModel