On property changed implemented on viewBase

src/Avalonia.Markup.Declarative/ControlPropertyExtensions.cs

@@ -203,7 +203,7 @@ public static class ControlPropertyExtensions
     public static TElement Styles<TElement>(this TElement control, params Style[] styles)
         where TElement : Control
     {
-        foreach (var style in styles) 
+        foreach (var style in styles)
             control.Styles.Add(style);
 
         return control;

src/Avalonia.Markup.Declarative/PropertyState.cs

@@ -0,0 +1,40 @@
+using System;
+using System.Reflection;
+
+namespace Avalonia.Markup.Declarative
+{
+    internal class ViewPropertyState
+    {
+        private object _value;
+
+        public string Name { get; }
+        private PropertyInfo PropertyInfo { get; }
+        private ViewBase View { get; }
+
+        public ViewPropertyState(PropertyInfo propertyInfo, ViewBase view)
+        {
+            this.PropertyInfo = propertyInfo;
+            this.View = view;
+
+            this.Name = propertyInfo.Name;
+
+            _value = PropertyInfo.GetValue(View);
+        }
+
+        public bool CheckStateChangedAndUpdate()
+        {
+            var oldValue = _value;
+            _value = PropertyInfo.GetValue(View);
+
+            if (_value == null && oldValue != null)
+                return false;
+
+            if (_value != null && oldValue == null)
+                return false;
+
+            return
+                (_value == null && oldValue == null)
+                || (_value != null && !_value.Equals(oldValue));
+        }
+    }
+}

src/Avalonia.Markup.Declarative/ViewBase.cs

@@ -1,6 +1,9 @@
 using System;
+using System.Collections.Generic;
+using System.ComponentModel;
 using System.Diagnostics;
 using System.IO;
+using System.Linq;
 using System.Linq.Expressions;
 using System.Runtime.CompilerServices;
 using Avalonia.Controls;
@@ -62,7 +65,7 @@ public abstract class ViewBase<TViewModel> : ViewBase
 /// <summary>
 /// Base view class used like UserControl in XAML
 /// </summary>
-public abstract class ViewBase : Decorator, IReloadable
+public abstract class ViewBase : Decorator, IReloadable, INotifyPropertyChanged
 {
     public event Action ViewInitialized;
 
@@ -110,6 +113,8 @@ public abstract class ViewBase : Decorator, IReloadable
     {
         try
         {
+            InitStateMembers();
+
             var content = Build();
             Child = content as Control;
 
@@ -194,6 +199,34 @@ public abstract class ViewBase : Decorator, IReloadable
         return asset;
     }
 
+
+    ViewPropertyState[]? _propertyStates = null;
+    private void InitStateMembers()
+    {
+        var viewType = GetType();
+        _propertyStates = viewType
+            .GetProperties()
+            .Where(p => p.DeclaringType == viewType)
+            .Select(p => new ViewPropertyState(p, this))
+            .ToArray();
+    }
+
+    protected void StateHasChnaged()
+    {
+        if (_propertyStates == null)
+            return;
+
+        foreach (var prop in _propertyStates)
+            if (prop.CheckStateChangedAndUpdate())
+                OnPropertyChanged(prop.Name);
+    }
+
+    public new event PropertyChangedEventHandler? PropertyChanged;
+    protected void OnPropertyChanged([CallerMemberName] string propertyName = null)
+    {
+        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
+    }
+
     #region Hot reload stuff
 
     protected override void OnAttachedToVisualTree(VisualTreeAttachmentEventArgs e)

src/Samples/AvaloniaMarkupSample/MvuSample/MvuSampleView.cs

@@ -6,17 +6,19 @@ public class MvuSampleView : ViewBase
         new StackPanel()
             .Children(
                 new TextBlock()
-                    .Text(@MyProperty),
+                    .Text(@MyProperty, bindingSource: this),
 
                 new Button()
-                    .Content("Click me")
+                    .Content("Click me " + @MyProperty1)
                     .OnClick(OnButtonClick)
             );
 
     public string MyProperty { get; set; } = "Hello MVU";
+    public string MyProperty1 { get; set; } = "No changes";
 
     private void OnButtonClick(RoutedEventArgs obj)
     {
-        throw new NotImplementedException();
+        MyProperty = "Button was clicked!";
+        StateHasChnaged();
     }
 }