moved converter code to extension class

PropertyInfoExtension.cs

@@ -0,0 +1,44 @@
+using System;
+using System.Reflection;
+using System.Text.Json;
+
+namespace ModernWpfPlayground
+{
+    public static class PropertyInfoExtension
+    {
+        public static PropertyInfo? Find(this PropertyInfo[] infos, string key) => Array.Find(infos, x => x.Name == key);
+
+        public static object? Convert(this PropertyInfo? propertyInfo, JsonElement value)
+        {
+            if (propertyInfo == default) return default;
+
+
+            if (propertyInfo.PropertyType == typeof(double))
+            {
+                return value.GetDouble();
+            }
+
+            if (propertyInfo.PropertyType == typeof(bool))
+            {
+                return value.GetBoolean();
+            }
+
+            if (propertyInfo.PropertyType == typeof(int))
+            {
+                return value.GetInt32();
+            }
+
+            if (propertyInfo.PropertyType.IsEnum)
+            {
+                return Enum.ToObject(propertyInfo.PropertyType, value.GetInt32());
+            }
+
+            if (propertyInfo.PropertyType == typeof(string))
+            {
+                return value.GetString();
+            }
+
+            return default;
+        }
+    }
+}

WindowViewModel.cs

@@ -1,5 +1,4 @@
-using System;
+using System.Collections.Generic;
-using System.Collections.Generic;
 using System.IO;
 using System.Reflection;
 using System.Text.Json;
@@ -108,43 +107,6 @@ namespace ModernWpfPlayground
 
         public ICommand ResetViewModelCommand { get; }
 
-        private object? CastToType(string key, JsonElement value)
-        {
-
-            var property = Array.Find(_properties, x => x.Name == key);
-            if (property == null)
-            {
-                return default;
-            }
-
-            if (property.PropertyType == typeof(double))
-            {
-                return value.GetDouble();
-            }
-
-            if (property.PropertyType == typeof(bool))
-            {
-                return value.GetBoolean();
-            }
-
-            if (property.PropertyType == typeof(int))
-            {
-                return value.GetInt32();
-            }
-
-            if (property.PropertyType.IsEnum)
-            {
-                return Enum.ToObject(property.PropertyType, value.GetInt32());
-            }
-
-            if (property.PropertyType == typeof(string))
-            {
-                return value.GetString();
-            }
-
-            return default;
-        }
-
         private void SaveViewModel()
         {
             var contents = JsonSerializer.Serialize(Values);
@@ -169,7 +131,7 @@ namespace ModernWpfPlayground
             var obj = JsonSerializer.Deserialize<Dictionary<string, JsonElement>>(contents);
             foreach (var (key, value) in obj)
             {
-                yield return (key, CastToType(key, value));
+                yield return (key, _properties.Find(key).Convert(value));
             }
         }
     }