Avoid unnecessary boxing of default values

Author: SteveSandersonMS

src/Components/src/Microsoft.AspNetCore.Components/ParameterCollectionExtensions.cs

@@ -66,7 +66,7 @@ public static void SetParameterProperties(
 
             foreach (var nonUsedParameter in localParameterWriter)
             {
-                nonUsedParameter.SetValue(target, nonUsedParameter.GetDefaultValue());
+                nonUsedParameter.SetDefaultValue(target);
             }
         }
 

src/Components/src/Microsoft.AspNetCore.Components/Reflection/IPropertySetter.cs

@@ -1,14 +1,12 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-using System;
-
 namespace Microsoft.AspNetCore.Components.Reflection
 {
     internal interface IPropertySetter
     {
         void SetValue(object target, object value);
 
-        object GetDefaultValue();
+        void SetDefaultValue(object target);
     }
 }

src/Components/src/Microsoft.AspNetCore.Components/Reflection/MemberAssignment.cs

@@ -43,23 +43,19 @@ public static IPropertySetter CreatePropertySetter(Type targetType, PropertyInfo
         class PropertySetter<TTarget, TValue> : IPropertySetter
         {
             private readonly Action<TTarget, TValue> _setterDelegate;
-            private object _defaultValue;
 
             public PropertySetter(MethodInfo setMethod)
             {
                 _setterDelegate = (Action<TTarget, TValue>)Delegate.CreateDelegate(
                     typeof(Action<TTarget, TValue>), setMethod);
                 var propertyType = typeof(TValue);
-                _defaultValue = propertyType.IsValueType ? Activator.CreateInstance(propertyType) : null;
             }
 
             public void SetValue(object target, object value)
                 => _setterDelegate((TTarget)target, (TValue)value);
 
-            public object GetDefaultValue()
-            {
-                return _defaultValue;
-            }
+            public void SetDefaultValue(object target)
+                => _setterDelegate((TTarget)target, default);
         }
     }
 }