BindableBase class for implementing INotifyPropertyChanged using C# 6 features while targeting .NET 2.0 to .NET 4.0. Make sure to use the nameof() operator for passing the propertyName parameter.

BindableBase.cs

    using System.ComponentModel;
    
    /// <summary>
    ///     Implementation of <see cref="INotifyPropertyChanged" /> to simplify models.
    /// </summary>
    public abstract class BindableBase : INotifyPropertyChanged
    {
        /// <summary>
        ///     Multicast event for property change notifications.
        /// </summary>
        public event PropertyChangedEventHandler PropertyChanged;

        /// <summary>
        ///     Checks if a property already matches a desired value.  Sets the property and
        ///     notifies listeners only when necessary.
        /// </summary>
        /// <typeparam name="T">Type of the property.</typeparam>
        /// <param name="storage">Reference to a property with both getter and setter.</param>
        /// <param name="value">Desired value for the property.</param>
        /// <param name="propertyName">Name of the property used to notify listeners.</param>
        /// <returns>
        ///     True if the value was changed, false if the existing value matched the
        ///     desired value.
        /// </returns>
        protected bool SetProperty<T>(ref T storage, T value, string propertyName)
        {
            if (Equals(storage, value))
            {
                return false;
            }

            storage = value;
            this.OnPropertyChanged(propertyName);
            return true;
        }

        /// <summary>
        ///     Notifies listeners that a property value has changed.
        /// </summary>
        /// <param name="propertyName">Name of the property used to notify listeners./>.
        /// </param>
        protected void OnPropertyChanged(string propertyName)
        {
            this.PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }
    }