FrameworkExtensions.PresentationCore 1.0.0.37

Extensions to WPF

Extension methods, observable collection types, and threading utilities for Windows Presentation Foundation (WPF), part of Hawkynt's .NET Framework Extensions.

Overview

This library provides WPF-specific utilities including dispatcher-aware observable collections, GDI+ to WPF image conversion, safe cross-thread event invocation, and extension methods for WPF controls. All types are designed to integrate seamlessly with WPF's dispatcher-based threading model and data-binding infrastructure.

API Reference

Observable Collections

ObservableDictionary<TKey, TValue> (class)

Namespace: System.Collections.ObjectModel

A dictionary that implements IDictionary<TKey, TValue>, INotifyCollectionChanged, and INotifyPropertyChanged. All mutating operations are automatically marshaled to the WPF dispatcher thread. When values implement INotifyPropertyChanged or INotifyCollectionChanged, the dictionary subscribes to their change events and propagates notifications upward.

ObservableList<T> (class)

Namespace: System.Collections.Specialized

Constraint: T : INotifyPropertyChanged

A thread-safe, dispatcher-aware list implementing IList<T>, IList, and INotifyCollectionChanged. All mutating operations are marshaled to the associated dispatcher thread and protected by a lock for thread safety.

Image Conversion

Image Extensions (System.Drawing.Image)

Static class: ImageExtensions

Namespace: System.Drawing

Availability: .NET Framework only (excluded from .NET Core and .NET 5+)

WPF Control Extensions

ItemCollection Extensions (System.Windows.Controls.ItemCollection)

Static class: ItemCollectionExtensions

Selector Extensions (System.Windows.Controls.Primitives.Selector)

Static class: SelectorExtensions

Dispatcher & Threading

DispatcherObject Extensions (System.Windows.Threading.DispatcherObject)

Static class: DispatcherObjectExtensions

Event Extensions (System.Windows.Threading)

Static class: EventExtensions

Safe event invocation methods that respect WPF's dispatcher model. Each subscriber in the invocation list is automatically marshaled to its owning dispatcher thread if it is a DispatcherObject.

Usage Examples

Using ObservableDictionary with WPF data binding

using System.Collections.ObjectModel;

var dict = new ObservableDictionary<string, int>();
dict.CollectionChanged += (s, e) => Console.WriteLine($"Action: {e.Action}");
dict.Add("apples", 3);
dict.Add("bananas", 5);
dict.Remove("apples");

Using ObservableList with dispatcher awareness

using System.Collections.Specialized;

var list = new ObservableList<MyViewModel>();
list.CollectionChanged += (s, e) => UpdateUI();
// Safe to call from any thread - automatically dispatches to UI thread
list.Add(new MyViewModel { Name = "Item 1" });
list.AddRange(new[] { viewModel2, viewModel3 });

Converting a GDI+ image to WPF BitmapImage

using System.Drawing;

var bitmap = new Bitmap(@"C:\Images\photo.png");
var wpfImage = bitmap.ToBitmapImage();
myWpfImageControl.Source = wpfImage;

Safe cross-thread event invocation

using System.Windows.Threading;

// In a background service or ViewModel:
public event EventHandler<DataEventArgs> DataReady;

// Invoke safely - each subscriber gets the event on its own dispatcher thread
DataReady.SafeInvoke(this, new DataEventArgs(result));

// Or fire-and-forget asynchronously
DataReady.AsyncSafeInvoke(this, new DataEventArgs(result));

Safely invoking actions on WPF controls

using System.Windows.Threading;

// From any thread, safely update a UI element
myTextBlock.SafelyInvoke(() => myTextBlock.Text = "Updated!");

// Run a long operation off the UI thread
myControl.Async(() => {
  var data = LoadDataFromDatabase();
  myControl.SafelyInvoke(() => myGrid.ItemsSource = data);
});

Installation

dotnet add package FrameworkExtensions.PresentationCore

Dependencies

• Backports (project reference)
• WPF (UseWpf enabled in project)

License

LGPL 3.0 or later - See LICENSE for details