Finish MPN00Bs

HorseIsleServer/MPN00BS/MiniMvvm/ViewModelBase.cs

@@ -0,0 +1,26 @@
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Reactive.Joins;
+using System.Runtime.CompilerServices;
+
+namespace MiniMvvm
+{
+    public class ViewModelBase : INotifyPropertyChanged
+    {
+        public event PropertyChangedEventHandler PropertyChanged;
+        protected bool RaiseAndSetIfChanged<T>(ref T field, T value, [CallerMemberName] string propertyName = null)
+        {
+            if (!EqualityComparer<T>.Default.Equals(field, value))
+            {
+                field = value;
+                RaisePropertyChanged(propertyName);
+                return true;
+            }
+            return false;
+        }
+
+
+        protected void RaisePropertyChanged([CallerMemberName] string propertyName = null)
+            => PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
+    }
+}