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Ecng.ComponentModel 1.0.451

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<T>

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