diff --git a/DeedyDesigner/Deedy.Testing/ExternalTypeConverter.cs b/DeedyDesigner/Deedy.Testing/ExternalTypeConverter.cs
new file mode 100644
index 0000000..567de56
--- /dev/null
+++ b/DeedyDesigner/Deedy.Testing/ExternalTypeConverter.cs
@@ -0,0 +1,49 @@
+using System;
+using System.ComponentModel;
+using System.ComponentModel.DataAnnotations;
+using System.Diagnostics.CodeAnalysis;
+using System.Globalization;
+
+
+/*
+public partial class App : Application
+{
+    protected override void OnStartup(StartupEventArgs e)
+    {
+        base.OnStartup(e);
+        
+        // 注册外部类型的「TypeConverter」
+        TypeDescriptor.AddAttributes(typeof(ExternalPerson), 
+            new TypeConverterAttribute(typeof(ExternalPersonConverter)));
+    }
+}
+*/
+
+
+
+// 在目标程序集中定义类型时添加转换器
+[TypeConverter(typeof(ExternalTypeConverter))]
+public class ExternalType {
+    public ExternalType(string? value) { }
+}
+// 在主程序集中定义元数据类
+[TypeConverter(typeof(ExternalTypeConverter))]
+public class ExternalTypeMetadata { }
+
+// 关联元数据与外部类型
+[MetadataType(typeof(ExternalTypeMetadata))]
+public partial class ExternalTypeProxy
+{
+    // 通过代理类访问外部类型
+    [AllowNull]
+    public ExternalType Target { get; set; }
+}
+public class ExternalTypeConverter : TypeConverter
+{
+    public override bool CanConvertFrom(ITypeDescriptorContext? context, Type sourceType) => sourceType == typeof(string);
+
+    public override object? ConvertFrom(ITypeDescriptorContext? context, CultureInfo? culture, object value)
+    {
+        return new ExternalType(value.ToString());
+    }
+}
\ No newline at end of file