Move design-time handling of events...

...to `Avalonia.Markup.Xaml`. Also added tests: tests required a new instance of `AvaloniaXamlSchemaContext` for each `AvaloniaXamlLoader` as otherwise one test can affect other tests.

src/Avalonia.DesignerSupport/DesignWindowLoader.cs

@@ -12,11 +12,6 @@ namespace Avalonia.DesignerSupport
 {
     public class DesignWindowLoader
     {
-        static DesignWindowLoader()
-        {
-            AvaloniaTypeConverters.Register(typeof(EventInfo), typeof(DesignerEventConverter));
-        }
-
         public static Window LoadDesignerWindow(string xaml, string assemblyPath, string xamlFileProjectPath)
         {
             Window window;

src/Markup/Avalonia.Markup.Xaml/Avalonia.Markup.Xaml.csproj

@@ -9,6 +9,7 @@
     <ItemGroup>
         <Compile Include="AvaloniaXamlLoader.cs" />
         <Compile Include="Converters\AvaloniaUriTypeConverter.cs" />
+        <Compile Include="Converters\AvaloniaEventConverter.cs" />
         <Compile Include="Converters\FontFamilyTypeConverter.cs" />
         <Compile Include="Converters\MemberSelectorTypeConverter.cs" />
         <Compile Include="Converters\NullableTypeConverter.cs" />

src/Markup/Avalonia.Markup.Xaml/AvaloniaTypeConverters.cs

@@ -11,6 +11,7 @@ using Avalonia.Controls.Templates;
 
 namespace Avalonia.Markup.Xaml
 {
+    using System.Reflection;
     using Avalonia.Media;
 
     /// <summary>
@@ -41,7 +42,8 @@ namespace Avalonia.Markup.Xaml
             { typeof(WindowIcon), typeof(IconTypeConverter) },
             { typeof(CultureInfo), typeof(CultureInfoConverter) },
             { typeof(Uri), typeof(AvaloniaUriTypeConverter) },
-            { typeof(FontFamily), typeof(FontFamilyTypeConverter) }
+            { typeof(FontFamily), typeof(FontFamilyTypeConverter) },
+            { typeof(EventInfo), typeof(AvaloniaEventConverter) },
         };
 
         internal static Type GetBuiltinTypeConverter(Type type)

src/Markup/Avalonia.Markup.Xaml/AvaloniaXamlLoader.cs

@@ -1,21 +1,20 @@
 // Copyright (c) The Avalonia Project. All rights reserved.
 // Licensed under the MIT license. See licence.md file in the project root for full license information.
 
-using Avalonia.Controls;
-using Avalonia.Markup.Data;
-using Avalonia.Markup.Xaml.PortableXaml;
-using Avalonia.Platform;
-using Portable.Xaml;
 using System;
 using System.Collections.Generic;
 using System.ComponentModel;
 using System.IO;
+using System.Linq;
 using System.Reflection;
 using System.Runtime.Serialization;
-using System.Runtime.Serialization.Json;
 using System.Text;
 using System.Xml.Linq;
-using System.Linq;
+using Avalonia.Controls;
+using Avalonia.Markup.Data;
+using Avalonia.Markup.Xaml.PortableXaml;
+using Avalonia.Platform;
+using Portable.Xaml;
 
 namespace Avalonia.Markup.Xaml
 {
@@ -24,7 +23,7 @@ namespace Avalonia.Markup.Xaml
     /// </summary>
     public class AvaloniaXamlLoader
     {
-        private readonly AvaloniaXamlSchemaContext _context = GetContext();
+        private readonly AvaloniaXamlSchemaContext _context = AvaloniaXamlSchemaContext.Create();
 
         public bool IsDesignMode
         {
@@ -32,22 +31,6 @@ namespace Avalonia.Markup.Xaml
             set => _context.IsDesignMode = value;
         }
 
-        private static AvaloniaXamlSchemaContext GetContext()
-        {
-            var result = AvaloniaLocator.Current.GetService<AvaloniaXamlSchemaContext>();
-
-            if (result == null)
-            {
-                result = AvaloniaXamlSchemaContext.Create();
-
-                AvaloniaLocator.CurrentMutable
-                    .Bind<AvaloniaXamlSchemaContext>()
-                    .ToConstant(result);
-            }
-
-            return result;
-        }
-
         /// <summary>
         /// Initializes a new instance of the <see cref="AvaloniaXamlLoader"/> class.
         /// </summary>

src/Avalonia.DesignerSupport/DesignerEventConverter.cs → src/Markup/Avalonia.Markup.Xaml/Converters/AvaloniaEventConverter.cs

@@ -4,11 +4,13 @@ using System.Globalization;
 using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
+using Avalonia.Controls;
+using Avalonia.Markup.Xaml.PortableXaml;
 using Portable.Xaml;
 
-namespace Avalonia.DesignerSupport
+namespace Avalonia.Markup.Xaml.Converters
 {
-    internal class DesignerEventConverter : TypeConverter
+    internal class AvaloniaEventConverter : TypeConverter
     {
         public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)
         {
@@ -72,13 +74,23 @@ namespace Avalonia.DesignerSupport
                         }
                     }
 
-                    // We want to ignore missing events in the designer, so if event handler
-                    // wasn't found create an empty delegate.
-                    var lambdaExpression = Expression.Lambda(
-                        eventType,
-                        Expression.Empty(),
-                        eventParameters.Select(x => Expression.Parameter(x.ParameterType)));
-                    return lambdaExpression.Compile();
+                    var contextProvider = (IXamlSchemaContextProvider)context.GetService(typeof(IXamlSchemaContextProvider));
+                    var avaloniaContext = (AvaloniaXamlSchemaContext)contextProvider.SchemaContext;
+
+                    if (avaloniaContext.IsDesignMode)
+                    {
+                        // We want to ignore missing events in the designer, so if event handler
+                        // wasn't found create an empty delegate.
+                        var lambdaExpression = Expression.Lambda(
+                            eventType,
+                            Expression.Empty(),
+                            eventParameters.Select(x => Expression.Parameter(x.ParameterType)));
+                        return lambdaExpression.Compile();
+                    }
+                    else
+                    {
+                        throw new XamlObjectWriterException($"Referenced value method {text} in type {target.GetType()} indicated by event {eventType.FullName} was not found");
+                    }
                 }
             }
             return base.ConvertFrom(context, culture, value);

src/Markup/Avalonia.Markup.Xaml/PortableXaml/portable.xaml.github

@@ -1 +1 @@
-Subproject commit 5d2edfcc1b2988f80303b1b2f3dd2b7c3de53db7
+Subproject commit ab5526173722b8988bc5ca3c03c8752ce89c0975

tests/Avalonia.Markup.Xaml.UnitTests/Xaml/EventTests.cs

@@ -0,0 +1,66 @@
+// Copyright (c) The Avalonia Project. All rights reserved.
+// Licensed under the MIT license. See licence.md file in the project root for full license information.
+
+using System;
+using Avalonia.Controls;
+using Avalonia.Input;
+using Portable.Xaml;
+using Xunit;
+
+namespace Avalonia.Markup.Xaml.UnitTests.Xaml
+{
+    public class EventTests
+    {
+        [Fact]
+        public void Event_Is_Attached()
+        {
+            var xaml = @"<Button xmlns='https://github.com/avaloniaui' Click='OnClick'/>";
+            var loader = new AvaloniaXamlLoader();
+            var target = new MyButton();
+
+            loader.Load(xaml, rootInstance: target);
+            RaiseClick(target);
+
+            Assert.True(target.Clicked);
+        }
+
+        [Fact]
+        public void Exception_Is_Thrown_If_Event_Not_Found()
+        {
+            var xaml = @"<Button xmlns='https://github.com/avaloniaui' Click='NotFound'/>";
+            var loader = new AvaloniaXamlLoader();
+            var target = new MyButton();
+
+            Assert.Throws<XamlObjectWriterException>(() => loader.Load(xaml, rootInstance: target));
+        }
+
+        [Fact]
+        public void Exception_Is_Not_Thrown_If_Event_Not_Found_In_Design_Mode()
+        {
+            var xaml = @"<Button xmlns='https://github.com/avaloniaui' Click='NotFound'/>";
+            var loader = new AvaloniaXamlLoader { IsDesignMode = true };
+            var target = new MyButton();
+
+            loader.Load(xaml, rootInstance: target);
+        }
+
+        private void RaiseClick(MyButton target)
+        {
+            target.RaiseEvent(new KeyEventArgs
+            {
+                RoutedEvent = Button.KeyDownEvent,
+                Key = Key.Enter,
+            });
+        }
+
+        class MyButton : Button
+        {
+            public bool Clicked { get; private set; }
+
+            public void OnClick(object sender, EventArgs e)
+            {
+                Clicked = true;
+            }
+        }
+    }
+}