Use a dynamically-emitted trampoline method so we can handle the "execute method has a return type" case cleanly.

This also provides a location for us to add any other trampolines that we need to emit.

src/Avalonia.Build.Tasks/XamlCompilerTaskExecutor.cs

@@ -124,6 +124,8 @@ namespace Avalonia.Build.Tasks
             var indexerAccessorClosure = new TypeDefinition("CompiledAvaloniaXaml", "!IndexerAccessorFactoryClosure",
                 TypeAttributes.Class, asm.MainModule.TypeSystem.Object);
             asm.MainModule.Types.Add(indexerAccessorClosure);
+            var trampolineBuilder = new TypeDefinition("CompiledAvaloniaXaml", "XamlIlTrampolines",
+                TypeAttributes.Class, asm.MainModule.TypeSystem.Object);
 
             var (xamlLanguage , emitConfig) = AvaloniaXamlIlLanguage.Configure(typeSystem);
             var compilerConfig = new AvaloniaXamlIlCompilerConfiguration(typeSystem,
@@ -133,6 +135,7 @@ namespace Avalonia.Build.Tasks
                 AvaloniaXamlIlLanguage.CustomValueConverter,
                 new XamlIlClrPropertyInfoEmitter(typeSystem.CreateTypeBuilder(clrPropertiesDef)),
                 new XamlIlPropertyInfoAccessorFactoryEmitter(typeSystem.CreateTypeBuilder(indexerAccessorClosure)),
+                new XamlIlTrampolineBuilder(typeSystem.CreateTypeBuilder(trampolineBuilder)),
                 new DeterministicIdGenerator());
 
 
@@ -256,7 +259,7 @@ namespace Avalonia.Build.Tasks
                             (closureName, closureBaseType) =>
                                 populateBuilder.DefineSubType(closureBaseType, closureName, false),
                             (closureName, returnType, parameterTypes) =>
-                                populateBuilder.CreateDelegateSubType(closureName, false, returnType, parameterTypes),
+                                populateBuilder.DefineDelegateSubType(closureName, false, returnType, parameterTypes),
                             res.Uri, res
                         );
                         

src/Markup/Avalonia.Markup.Xaml.Loader/AvaloniaXamlIlRuntimeCompiler.cs

@@ -177,11 +177,13 @@ namespace Avalonia.Markup.Xaml.XamlIl
             var tb = _sreBuilder.DefineType("Builder_" + Guid.NewGuid().ToString("N") + "_" + uri);
             var clrPropertyBuilder = tb.DefineNestedType("ClrProperties_" + Guid.NewGuid().ToString("N"));
             var indexerClosureType = _sreBuilder.DefineType("IndexerClosure_" + Guid.NewGuid().ToString("N"));
+            var trampolineBuilder = _sreBuilder.DefineType("Trampolines_" + Guid.NewGuid().ToString("N"));
 
             var compiler = new AvaloniaXamlIlCompiler(new AvaloniaXamlIlCompilerConfiguration(_sreTypeSystem, asm,
                 _sreMappings, _sreXmlns, AvaloniaXamlIlLanguage.CustomValueConverter,
                 new XamlIlClrPropertyInfoEmitter(_sreTypeSystem.CreateTypeBuilder(clrPropertyBuilder)),
-                new XamlIlPropertyInfoAccessorFactoryEmitter(_sreTypeSystem.CreateTypeBuilder(indexerClosureType))), 
+                new XamlIlPropertyInfoAccessorFactoryEmitter(_sreTypeSystem.CreateTypeBuilder(indexerClosureType)),
+                new XamlIlTrampolineBuilder(_sreTypeSystem.CreateTypeBuilder(trampolineBuilder))), 
                 _sreEmitMappings,
                 _sreContextType) { EnableIlVerification = true };
             
@@ -196,6 +198,7 @@ namespace Avalonia.Markup.Xaml.XamlIl
             compiler.ParseAndCompile(xaml, uri?.ToString(), null, _sreTypeSystem.CreateTypeBuilder(tb), overrideType);
             var created = tb.CreateTypeInfo();
             clrPropertyBuilder.CreateTypeInfo();
+            trampolineBuilder.CreateTypeInfo();
 
             return LoadOrPopulate(created, rootInstance);
         }

src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/AvaloniaXamlIlCompilerConfiguration.cs

@@ -7,6 +7,7 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions
     {
         public XamlIlClrPropertyInfoEmitter ClrPropertyEmitter { get; }
         public XamlIlPropertyInfoAccessorFactoryEmitter AccessorFactoryEmitter { get; }
+        public XamlIlTrampolineBuilder TrampolineBuilder { get; }
 
         public AvaloniaXamlIlCompilerConfiguration(IXamlTypeSystem typeSystem, 
             IXamlAssembly defaultAssembly, 
@@ -15,13 +16,16 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions
             XamlValueConverter customValueConverter,
             XamlIlClrPropertyInfoEmitter clrPropertyEmitter,
             XamlIlPropertyInfoAccessorFactoryEmitter accessorFactoryEmitter,
+            XamlIlTrampolineBuilder trampolineBuilder,
             IXamlIdentifierGenerator identifierGenerator = null)
             : base(typeSystem, defaultAssembly, typeMappings, xmlnsMappings, customValueConverter, identifierGenerator)
         {
             ClrPropertyEmitter = clrPropertyEmitter;
             AccessorFactoryEmitter = accessorFactoryEmitter;
+            TrampolineBuilder = trampolineBuilder;
             AddExtra(ClrPropertyEmitter);
             AddExtra(AccessorFactoryEmitter);
+            AddExtra(TrampolineBuilder);
         }
     }
 }

src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlWellKnownTypes.cs

@@ -86,6 +86,7 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
         public IXamlType IBrush { get; }
         public IXamlType ImmutableSolidColorBrush { get; }
         public IXamlConstructor ImmutableSolidColorBrushConstructorColor { get; }
+        public IXamlType TypeUtilities { get; }
 
         public AvaloniaXamlIlWellKnownTypes(TransformerConfiguration cfg)
         {
@@ -189,6 +190,7 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
             IBrush = cfg.TypeSystem.GetType("Avalonia.Media.IBrush");
             ImmutableSolidColorBrush = cfg.TypeSystem.GetType("Avalonia.Media.Immutable.ImmutableSolidColorBrush");
             ImmutableSolidColorBrushConstructorColor = ImmutableSolidColorBrush.GetConstructor(new List<IXamlType> { UInt });
+            TypeUtilities = cfg.TypeSystem.GetType("Avalonia.Utilities.TypeUtilities");
         }
     }
 

src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/XamlIlBindingPathHelper.cs

@@ -14,7 +14,7 @@ using XamlX.Emit;
 using XamlX.IL;
 using Avalonia.Utilities;
 
-using XamlIlEmitContext = XamlX.Emit.XamlEmitContext<XamlX.IL.IXamlILEmitter, XamlX.IL.XamlILNodeEmitResult>;
+using XamlIlEmitContext = XamlX.Emit.XamlEmitContextWithLocals<XamlX.IL.IXamlILEmitter, XamlX.IL.XamlILNodeEmitResult>;
 
 namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions
 {
@@ -652,58 +652,56 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions
 
             public void Emit(XamlIlEmitContext context, IXamlILEmitter codeGen)
             {
+                var trampolineBuilder = context.Configuration.GetExtra<XamlIlTrampolineBuilder>();
+                var objectType = context.Configuration.WellKnownTypes.Object;
                 codeGen
-                    .Ldtoken(_executeMethod);
-
-                if (_canExecuteMethod is not null)
+                    .Ldstr(_executeMethod.Name)
+                    .Ldnull()
+                    .Ldftn(trampolineBuilder.EmitCommandExecuteTrampoline(context, _executeMethod))
+                    .Newobj(context.Configuration.TypeSystem.GetType("System.Action`2")
+                        .MakeGenericType(objectType, objectType)
+                        .GetConstructor(new() { objectType, context.Configuration.TypeSystem.GetType("System.IntPtr") }));
+
+                if (_canExecuteMethod is null)
                 {
-                    codeGen.Ldtoken(_canExecuteMethod);
+                    codeGen.Ldnull();
                 }
                 else
                 {
-                    using var canExecuteMethodHandle = codeGen.LocalsPool.GetLocal(context.Configuration.TypeSystem.GetType("System.RuntimeMethodHandle"));
                     codeGen
-                        .Ldloca(canExecuteMethodHandle.Local)
-                        .Emit(OpCodes.Initobj)
-                        .Ldloc(canExecuteMethodHandle.Local);
+                        .Ldnull()
+                        .Ldftn(trampolineBuilder.EmitCommandCanExecuteTrampoline(context, _canExecuteMethod))
+                        .Newobj(context.Configuration.TypeSystem.GetType("System.Func`3")
+                            .MakeGenericType(objectType, objectType, context.Configuration.WellKnownTypes.Boolean)
+                            .GetConstructor(new() { objectType, context.Configuration.TypeSystem.GetType("System.IntPtr") }));
                 }
 
-                if (_dependsOnProperties is { Count:> 0 })
+                if (_dependsOnProperties is { Count:> 1 })
                 {
-                    using var dependsOnProperties = codeGen.LocalsPool.GetLocal(context.Configuration.WellKnownTypes.String.MakeArrayType(1));
+                    using var dependsOnPropertiesArray = context.GetLocalOfType(context.Configuration.WellKnownTypes.String.MakeArrayType(1));
                     codeGen
                         .Ldc_I4(_dependsOnProperties.Count)
                         .Newarr(context.Configuration.WellKnownTypes.String)
-                        .Stloc(dependsOnProperties.Local);
+                        .Stloc(dependsOnPropertiesArray.Local);
 
-                    for (var i = 0; i < _dependsOnProperties.Count; i++)
+                    for (int i = 0; i < _dependsOnProperties.Count; i++)
                     {
-                        var prop = _dependsOnProperties[i];
                         codeGen
-                            .Ldloc(dependsOnProperties.Local)
+                            .Ldloc(dependsOnPropertiesArray.Local)
                             .Ldc_I4(i)
-                            .Ldstr(prop)
+                            .Ldstr(_dependsOnProperties[i])
                             .Stelem_ref();
                     }
-                    codeGen.Ldloc(dependsOnProperties.Local);
+                    codeGen.Ldloc(dependsOnPropertiesArray.Local);
                 }
                 else
                 {
                     codeGen.Ldnull();
                 }
 
-                if (_executeMethod.Parameters.Count != 0)
-                {
-                    codeGen.EmitCall(
-                        context.GetAvaloniaTypes()
-                            .CompiledBindingPathBuilder.FindMethod(m => m.Name == "CommandWithParameter"));
-                }
-                else
-                {
-                    codeGen.EmitCall(
-                        context.GetAvaloniaTypes()
-                                .CompiledBindingPathBuilder.FindMethod(m => m.Name == "Command"));
-                }
+                codeGen
+                    .EmitCall(context.GetAvaloniaTypes()
+                        .CompiledBindingPathBuilder.FindMethod(m => m.Name == "Command"));
             }
         }
 
@@ -829,7 +827,7 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions
             }
         }
 
-        class XamlIlBindingPathNode : XamlAstNode, IXamlIlBindingPathNode, IXamlAstEmitableNode<IXamlILEmitter, XamlILNodeEmitResult>
+        class XamlIlBindingPathNode : XamlAstNode, IXamlIlBindingPathNode, IXamlAstLocalsEmitableNode<IXamlILEmitter, XamlILNodeEmitResult>
         {
             private readonly List<IXamlIlBindingPathElementNode> _transformElements;
 

src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/XamlIlTrampolineBuilder.cs

@@ -0,0 +1,117 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Text;
+using XamlX.Emit;
+using XamlX.IL;
+using XamlX.TypeSystem;
+using Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers;
+using System.Reflection.Emit;
+
+namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions
+{
+    internal class XamlIlTrampolineBuilder
+    {
+        private IXamlTypeBuilder<IXamlILEmitter> _builder;
+        private Dictionary<string, IXamlMethod> _trampolines = new();
+
+        public XamlIlTrampolineBuilder(IXamlTypeBuilder<IXamlILEmitter> builder)
+        {
+            _builder = builder;
+        }
+
+        public IXamlMethod EmitCommandExecuteTrampoline(XamlEmitContext<IXamlILEmitter, XamlILNodeEmitResult> context, IXamlMethod executeMethod)
+        {
+            Debug.Assert(!executeMethod.IsStatic);
+            string methodName = $"{executeMethod.DeclaringType.GetFqn()}+{executeMethod.Name}_{executeMethod.Parameters.Count}!CommandExecuteTrampoline";
+            if (_trampolines.TryGetValue(methodName, out var method))
+            {
+                return method;
+            }
+            var trampoline = _builder.DefineMethod(
+                context.Configuration.WellKnownTypes.Void,
+                new[] { context.Configuration.WellKnownTypes.Object, context.Configuration.WellKnownTypes.Object },
+                methodName,
+                true,
+                true,
+                false);
+            var gen = trampoline.Generator;
+            if (executeMethod.DeclaringType.IsValueType)
+            {
+                gen.Ldarg_0()
+                    .Unbox(executeMethod.DeclaringType);
+            }
+            else
+            {
+                gen.Ldarg_0()
+                    .Castclass(executeMethod.DeclaringType);
+            }
+            if (executeMethod.Parameters.Count != 0)
+            {
+                Debug.Assert(executeMethod.Parameters.Count == 1);
+                if (executeMethod.Parameters[0] != context.Configuration.WellKnownTypes.Object)
+                {
+                    var convertedValue = gen.DefineLocal(context.Configuration.WellKnownTypes.Object);
+                    gen.Ldtype(executeMethod.Parameters[0])
+                        .Ldarg(1)
+                        .EmitCall(context.Configuration.WellKnownTypes.CultureInfo.FindMethod(m => m.Name == "get_CurrentCulture"))
+                        .Ldloca(convertedValue)
+                        .EmitCall(
+                            context.GetAvaloniaTypes().TypeUtilities.FindMethod(m => m.Name == "TryConvert"),
+                            swallowResult: true)
+                        .Ldloc(convertedValue)
+                        .Unbox_Any(executeMethod.Parameters[0]);
+                }
+                else
+                {
+                    gen.Ldarg(1);
+                }
+            }
+            gen.Emit(OpCodes.Tailcall);
+            gen.EmitCall(executeMethod, swallowResult: true);
+            gen.Ret();
+
+            _trampolines.Add(methodName, trampoline);
+            return trampoline;
+        }
+
+        public IXamlMethod EmitCommandCanExecuteTrampoline(XamlEmitContext<IXamlILEmitter, XamlILNodeEmitResult> context, IXamlMethod canExecuteMethod)
+        {
+            Debug.Assert(!canExecuteMethod.IsStatic);
+            Debug.Assert(canExecuteMethod.Parameters.Count == 1);
+            Debug.Assert(canExecuteMethod.ReturnType == context.Configuration.WellKnownTypes.Boolean);
+            string methodName = $"{canExecuteMethod.DeclaringType.GetFqn()}+{canExecuteMethod.Name}!CommandCanExecuteTrampoline";
+            if (_trampolines.TryGetValue(methodName, out var method))
+            {
+                return method;
+            }
+            var trampoline = _builder.DefineMethod(
+                context.Configuration.WellKnownTypes.Boolean,
+                new[] { context.Configuration.WellKnownTypes.Object, context.Configuration.WellKnownTypes.Object },
+                methodName,
+                true,
+                true,
+                false);
+            if (canExecuteMethod.DeclaringType.IsValueType)
+            {
+                trampoline.Generator
+                    .Ldarg_0()
+                    .Unbox(canExecuteMethod.DeclaringType);
+            }
+            else
+            {
+                trampoline.Generator
+                    .Ldarg_0()
+                    .Castclass(canExecuteMethod.DeclaringType);
+            }
+            trampoline.Generator
+                .Ldarg(1)
+                .Emit(OpCodes.Tailcall)
+                .EmitCall(canExecuteMethod)
+                .Ret();
+
+            _trampolines.Add(methodName, trampoline);
+            return trampoline;
+        }
+    }
+}

src/Markup/Avalonia.Markup.Xaml/MarkupExtensions/CompiledBindings/CommandAccessorPlugin.cs

@@ -12,11 +12,15 @@ namespace Avalonia.Markup.Xaml.MarkupExtensions.CompiledBindings
 {
     internal class CommandAccessorPlugin : IPropertyAccessorPlugin
     {
-        private readonly Func<WeakReference<object>, IPropertyAccessor> _commandAccessorFactory;
+        private readonly Action<object, object> _execute;
+        private readonly Func<object, object, bool> _canExecute;
+        private readonly ISet<string> _dependsOnProperties;
 
-        public CommandAccessorPlugin(Func<WeakReference<object>, IPropertyAccessor> commandAccessorFactory)
+        public CommandAccessorPlugin(Action<object, object> execute, Func<object, object, bool> canExecute, ISet<string> dependsOnProperties)
         {
-            _commandAccessorFactory = commandAccessorFactory;
+            _execute = execute;
+            _canExecute = canExecute;
+            _dependsOnProperties = dependsOnProperties;
         }
 
         public bool Match(object obj, string propertyName)
@@ -26,25 +30,76 @@ namespace Avalonia.Markup.Xaml.MarkupExtensions.CompiledBindings
 
         public IPropertyAccessor Start(WeakReference<object> reference, string propertyName)
         {
-            return _commandAccessorFactory(reference);
+            return new CommandAccessor(reference, _execute, _canExecute, _dependsOnProperties);
         }
 
-        internal abstract class CommandAccessorBase : PropertyAccessorBase
+        private sealed class CommandAccessor : PropertyAccessorBase
         {
             private readonly WeakReference<object> _reference;
+            private Command _command;
             private readonly ISet<string> _dependsOnProperties;
 
-            public CommandAccessorBase(WeakReference<object> reference, ISet<string> dependsOnProperties)
+            public CommandAccessor(WeakReference<object> reference, Action<object, object> execute, Func<object, object, bool> canExecute, ISet<string> dependsOnProperties)
             {
                 Contract.Requires<ArgumentNullException>(reference != null);
 
                 _reference = reference;
                 _dependsOnProperties = dependsOnProperties;
+                _command = new Command(reference, execute, canExecute);
+
             }
 
-            public override Type PropertyType => typeof(ICommand);
+            public override object Value => _reference.TryGetTarget(out var _) ? _command : null;
+
+            private void RaiseCanExecuteChanged()
+            {
+                _command.RaiseCanExecuteChanged();
+            }
+
+            private sealed class Command : ICommand
+            {
+                private readonly WeakReference<object> _target;
+                private readonly Action<object, object> _execute;
+                private readonly Func<object, object, bool> _canExecute;
+
+                public event EventHandler CanExecuteChanged;
+
+                public Command(WeakReference<object> target, Action<object, object> execute, Func<object, object, bool> canExecute)
+                {
+                    _target = target;
+                    _execute = execute;
+                    _canExecute = canExecute;
+                }
+
+                public void RaiseCanExecuteChanged()
+                {
+                    Threading.Dispatcher.UIThread.Post(() => CanExecuteChanged?.Invoke(this, EventArgs.Empty)
+                       , Threading.DispatcherPriority.Input);
+                }
+
+                public bool CanExecute(object parameter)
+                {
+                    if (_target.TryGetTarget(out var target))
+                    {
+                        if (_canExecute == null)
+                        {
+                            return true;
+                        }
+                        return _canExecute(target, parameter);
+                    }
+                    return false;
+                }
 
-            protected abstract void RaiseCanExecuteChanged();
+                public void Execute(object parameter)
+                {
+                    if (_target.TryGetTarget(out var target))
+                    {
+                        _execute(target, parameter);
+                    }
+                }
+            }
+
+            public override Type PropertyType => typeof(ICommand);
 
             public override bool SetValue(object value, BindingPriority priority)
             {
@@ -55,7 +110,7 @@ namespace Avalonia.Markup.Xaml.MarkupExtensions.CompiledBindings
             {
                 if (string.IsNullOrEmpty(e.PropertyName) || _dependsOnProperties.Contains(e.PropertyName))
                 {
-                    SendCurrentValue();
+                    RaiseCanExecuteChanged();
                 }
             }
 
@@ -97,101 +152,5 @@ namespace Avalonia.Markup.Xaml.MarkupExtensions.CompiledBindings
                 }
             }
         }
-
-        internal sealed class CommandWithParameterAccessor<T> : CommandAccessorBase
-        {
-            private Command _command;
-
-            public CommandWithParameterAccessor(WeakReference<object> target, ISet<string> dependsOnProperties, Action<T> execute, Func<object, bool> canExecute)
-                : base(target, dependsOnProperties)
-            {
-                _command = new Command(execute, canExecute);
-            }
-
-            public override object Value => _command;
-
-            protected override void RaiseCanExecuteChanged()
-            {
-                _command.RaiseCanExecuteChanged();
-            }
-
-            private sealed class Command : ICommand
-            {
-                private readonly Action<T> _execute;
-                private readonly Func<object, bool> _canExecute;
-
-                public event EventHandler CanExecuteChanged;
-
-                public Command(Action<T> execute, Func<object, bool> canExecute)
-                {
-                    _execute = execute;
-                    _canExecute = canExecute;
-                }
-
-                public void RaiseCanExecuteChanged()
-                {
-                    Threading.Dispatcher.UIThread.Post(() => CanExecuteChanged?.Invoke(this, EventArgs.Empty)
-                       , Threading.DispatcherPriority.Input);
-                }
-
-                public bool CanExecute(object parameter)
-                {
-                    return _canExecute(parameter);
-                }
-
-                public void Execute(object parameter)
-                {
-                    _execute((T)parameter);
-                }
-            }
-        }
-
-        internal sealed class CommandWithoutParameterAccessor : CommandAccessorBase
-        {
-            private Command _command;
-
-            public CommandWithoutParameterAccessor(WeakReference<object> target, ISet<string> dependsOnProperties, Action execute, Func<object, bool> canExecute)
-                : base(target, dependsOnProperties)
-            {
-                _command = new Command(execute, canExecute);
-            }
-
-            public override object Value => _command;
-
-            protected override void RaiseCanExecuteChanged()
-            {
-                _command.RaiseCanExecuteChanged();
-            }
-
-            private sealed class Command : ICommand
-            {
-                private readonly Action _execute;
-                private readonly Func<object, bool> _canExecute;
-
-                public event EventHandler CanExecuteChanged;
-
-                public Command(Action execute, Func<object, bool> canExecute)
-                {
-                    _execute = execute;
-                    _canExecute = canExecute;
-                }
-
-                public void RaiseCanExecuteChanged()
-                {
-                    Threading.Dispatcher.UIThread.Post(() => CanExecuteChanged?.Invoke(this, EventArgs.Empty)
-                       , Threading.DispatcherPriority.Input);
-                }
-
-                public bool CanExecute(object parameter)
-                {
-                    return _canExecute(parameter);
-                }
-
-                public void Execute(object parameter)
-                {
-                    _execute();
-                }
-            }
-        }
     }
 }

src/Markup/Avalonia.Markup.Xaml/MarkupExtensions/CompiledBindings/CompiledBindingPath.cs

@@ -37,8 +37,8 @@ namespace Avalonia.Markup.Xaml.MarkupExtensions.CompiledBindings
                     case PropertyElement prop:
                         node = new PropertyAccessorNode(prop.Property.Name, enableValidation, new PropertyInfoAccessorPlugin(prop.Property, prop.AccessorFactory));
                         break;
-                    case IMethodAsCommandElement methodAsCommand:
-                        node = new PropertyAccessorNode(methodAsCommand.ExecuteMethod.Name, enableValidation, new CommandAccessorPlugin(methodAsCommand.CreateAccessor));
+                    case MethodAsCommandElement methodAsCommand:
+                        node = new PropertyAccessorNode(methodAsCommand.MethodName, enableValidation, new CommandAccessorPlugin(methodAsCommand.ExecuteMethod, methodAsCommand.CanExecuteMethod, methodAsCommand.DependsOnProperties));
                         break;
                     case MethodAsDelegateElement methodAsDelegate:
                         node = new PropertyAccessorNode(methodAsDelegate.Method.Name, enableValidation, new MethodAccessorPlugin(methodAsDelegate.Method, methodAsDelegate.DelegateType));
@@ -105,15 +105,9 @@ namespace Avalonia.Markup.Xaml.MarkupExtensions.CompiledBindings
             return this;
         }
 
-        public CompiledBindingPathBuilder Command(RuntimeMethodHandle executeMethod, RuntimeMethodHandle canExecuteMethod, string[] dependsOnProperties)
+        public CompiledBindingPathBuilder Command(string methodName, Action<object, object> executeHelper, Func<object, object, bool> canExecuteHelper, string[] dependsOnProperties)
         {
-            _elements.Add(new MethodAsCommandElement(executeMethod, canExecuteMethod, dependsOnProperties));
-            return this;
-        }
-
-        public CompiledBindingPathBuilder CommandWithParameter<T>(RuntimeMethodHandle executeMethod, RuntimeMethodHandle canExecuteMethod, string[] dependsOnProperties)
-        {
-            _elements.Add(new MethodAsCommandElement<T>(executeMethod, canExecuteMethod, dependsOnProperties));
+            _elements.Add(new MethodAsCommandElement(methodName, executeHelper, canExecuteHelper, dependsOnProperties ?? Array.Empty<string>()));
             return this;
         }
 
@@ -216,49 +210,20 @@ namespace Avalonia.Markup.Xaml.MarkupExtensions.CompiledBindings
         public Type DelegateType { get; }
     }
 
-    internal interface IMethodAsCommandElement
-    {
-        MethodInfo ExecuteMethod { get; }
-        IPropertyAccessor CreateAccessor(WeakReference<object> obj);
-    }
-
-    internal class MethodAsCommandElement : ICompiledBindingPathElement, IMethodAsCommandElement
-    {
-        public MethodAsCommandElement(RuntimeMethodHandle executeMethod, RuntimeMethodHandle canExecuteMethod, string[] dependsOnElements)
-        {
-            ExecuteMethod = (MethodInfo)MethodBase.GetMethodFromHandle(executeMethod);
-            CanExecuteMethod = canExecuteMethod != default ? (MethodInfo)MethodBase.GetMethodFromHandle(canExecuteMethod) : null;
-            DependsOnProperties = new HashSet<string>(dependsOnElements);
-        }
-
-        public MethodInfo ExecuteMethod { get; }
-        public MethodInfo CanExecuteMethod { get; }
-        public HashSet<string> DependsOnProperties { get; }
-
-        public IPropertyAccessor CreateAccessor(WeakReference<object> obj)
-        {
-            obj.TryGetTarget(out object target);
-            return new CommandAccessorPlugin.CommandWithoutParameterAccessor(obj, DependsOnProperties, (Action)ExecuteMethod.CreateDelegate(typeof(Action), target), (Func<object, bool>)CanExecuteMethod?.CreateDelegate(typeof(Func<object, bool>), target));
-        }
-    }
-    internal class MethodAsCommandElement<T> : ICompiledBindingPathElement, IMethodAsCommandElement
+    internal class MethodAsCommandElement : ICompiledBindingPathElement
     {
-        public MethodAsCommandElement(RuntimeMethodHandle executeMethod, RuntimeMethodHandle canExecuteMethod, string[] dependsOnElements)
+        public MethodAsCommandElement(string methodName, Action<object, object> executeHelper, Func<object, object, bool> canExecuteHelper, string[] dependsOnElements)
         {
-            ExecuteMethod = (MethodInfo)MethodBase.GetMethodFromHandle(executeMethod);
-            CanExecuteMethod = canExecuteMethod != default ? (MethodInfo)MethodBase.GetMethodFromHandle(canExecuteMethod) : null;
+            MethodName = methodName;
+            ExecuteMethod = executeHelper;
+            CanExecuteMethod = canExecuteHelper;
             DependsOnProperties = new HashSet<string>(dependsOnElements);
         }
 
-        public MethodInfo ExecuteMethod { get; }
-        public MethodInfo CanExecuteMethod { get; }
+        public string MethodName { get; }
+        public Action<object, object> ExecuteMethod { get; }
+        public Func<object, object, bool> CanExecuteMethod { get; }
         public HashSet<string> DependsOnProperties { get; }
-
-        public IPropertyAccessor CreateAccessor(WeakReference<object> obj)
-        {
-            obj.TryGetTarget(out object target);
-            return new CommandAccessorPlugin.CommandWithParameterAccessor<T>(obj, DependsOnProperties, (Action<T>)ExecuteMethod.CreateDelegate(typeof(Action<T>), target), (Func<object, bool>)CanExecuteMethod?.CreateDelegate(typeof(Func<object, bool>), target));
-        }
     }
 
     internal interface IStronglyTypedStreamElement : ICompiledBindingPathElement

tests/Avalonia.Markup.Xaml.UnitTests/MarkupExtensions/CompiledBindingExtensionTests.cs

@@ -1181,7 +1181,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
         xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'
         xmlns:local='clr-namespace:Avalonia.Markup.Xaml.UnitTests.MarkupExtensions;assembly=Avalonia.Markup.Xaml.UnitTests'
         x:DataType='local:MethodAsCommandDataContext'>
-    <Button Name='button' Command='{Binding Do}' CommandParameter='{CompiledBinding Parameter, Mode=OneTime}'/>
+    <Button Name='button' Command='{CompiledBinding Do}' CommandParameter='{CompiledBinding Parameter, Mode=OneTime}'/>
 </Window>";
                 var window = (Window)AvaloniaRuntimeXamlLoader.Load(xaml);
                 var button = window.FindControl<Button>("button");
@@ -1209,7 +1209,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
         xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'
         xmlns:local='clr-namespace:Avalonia.Markup.Xaml.UnitTests.MarkupExtensions;assembly=Avalonia.Markup.Xaml.UnitTests'
         x:DataType='local:MethodAsCommandDataContext'>
-    <Button Name='button' Command='{Binding Do}' CommandParameter='{CompiledBinding Parameter, Mode=OneWay}'/>
+    <Button Name='button' Command='{CompiledBinding Do}' CommandParameter='{CompiledBinding Parameter, Mode=OneWay}'/>
 </Window>";
                 var window = (Window)AvaloniaRuntimeXamlLoader.Load(xaml);
                 var button = window.FindControl<Button>("button");