ViewModel base class for WPF application.

ViewModelBase.cs

using System;
using System.Windows.Threading;
using System.Diagnostics;
using System.ComponentModel;
using System.Collections.Generic;
using System.Runtime.CompilerServices;
using System.Windows;

namespace ViewModels
{
	/// <summary>
	/// The base class of ViewModel which implements
	/// INotifyPropertyChanged interface.
	/// Also implements dispatcher method for multithreaded property access.
	/// </summary>
	internal class ViewModel : INotifyPropertyChanged
	{
		public event PropertyChangedEventHandler PropertyChanged;

		protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
			=> PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));

		protected bool SetField<T>(ref T field, T value, [CallerMemberName] string propertyName = null)
		{
			if (EqualityComparer<T>.Default.Equals(field, value)) return false;
			field = value;
			OnPropertyChanged(propertyName);
			return true;
		}

		/// <summary>
		/// Helper function to dispatch property access so that it can be done
		/// from background thread.
		/// </summary>
		/// <param name="f">side effect action to be performed.</param>
		protected void Dispatch(Action f) => Application.Current.Dispatcher.Invoke(f);

		/// <summary>
		/// Helper function to dispatch property access so that it can be done
		/// from background thread.
		/// </summary>
		/// <param name="f">side effect action to be performed.</param>
		protected TResult Dispatch<TResult>(Func<TResult> f) => Application.Current.Dispatcher.Invoke(f);
	}
}