INotifyPropertyChanged_Example.cs

// Example of INotifyPropertyChanged
//   * Other examples online were missing consumming the event itself.
//   * https://learn.microsoft.com/en-us/dotnet/api/system.componentmodel.inotifypropertychanged.propertychanged
// Can try running this example at: https://dotnetfiddle.net/pWjjGo

using System;

using System.ComponentModel;
using System.Runtime.CompilerServices;

public class Program
{
    public static void Main()
    {
        var model = new MyModel();
        model.PropertyChanged += onPropertyChanged;
        model.CustomerName = "Josh";
    }

    static void onPropertyChanged(object sender, PropertyChangedEventArgs e)
    {
        Console.WriteLine(
            "onPropertyChanged:sender: " + sender + " , e.PropertyName: " + e.PropertyName
        );
        if (e.PropertyName == "CustomerName")
        {
            // INotifyPropertyChanged API is not ideal
            // It's cumbersome for the consumer, it could cleaner if Microsoft used generics instead of requiring a cast
            var currentName = ((MyModel)sender).CustomerName;
            Console.WriteLine("name is now " + currentName);
        }
    }
}

class MyModel : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    private void NotifyPropertyChanged([CallerMemberName] string propertyName = "")
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
    }

    private string customerNameValue = string.Empty;
    public string CustomerName
    {
        get { return this.customerNameValue; }
        set
        {
            if (value != this.customerNameValue)
            {
                this.customerNameValue = value;
                NotifyPropertyChanged();
            }
        }
    }
}