.NET 4 中 ExpandoObject 类的引入引发了对其性能的质疑хэш-таблиц。虽然 ExpandoObject 提供了与这些数据结构类似的功能,但它拥有增强其实用性的独特优势。
ExpandoObject 的一个显着优势是它能够促进复杂分层对象的创建对象。随着嵌套字典变得笨重,ExpandoObject 提供了一种更优雅、更易读的解决方案。考虑以下示例:
Dictionary<String, object> dict = new Dictionary<string, object>(); Dictionary<String, object> address = new Dictionary<string,object>(); dict["Address"] = address; address["State"] = "WA"; Console.WriteLine(((Dictionary<string,object>)dict["Address"])["State"]);
与上述方法相比,ExpandoObject 允许更简洁直观的语法:
dynamic expando = new ExpandoObject(); expando.Address = new ExpandoObject(); expando.Address.State = "WA"; Console.WriteLine(expando.Address.State);
ExpandoObject 实现INotifyPropertyChanged 接口,与单纯的字典相比,赋予它对属性的额外控制。该接口使对象能够在属性值发生变化时通知观察者,从而促进数据绑定和属性验证场景。
最后,ExpandoObject 支持事件处理,允许您附加和分离其属性的事件处理程序。此功能提供了管理和响应对象事件的灵活性:
class Program { static void Main(string[] args) { dynamic d = new ExpandoObject(); // Initialize the event to null (meaning no handlers) d.MyEvent = null; // Add some handlers d.MyEvent += new EventHandler(OnMyEvent); d.MyEvent += new EventHandler(OnMyEvent2); // Fire the event EventHandler e = d.MyEvent; e?.Invoke(d, new EventArgs()); } static void OnMyEvent(object sender, EventArgs e) { Console.WriteLine("OnMyEvent fired by: {0}", sender); } static void OnMyEvent2(object sender, EventArgs e) { Console.WriteLine("OnMyEvent2 fired by: {0}", sender); } }
此外,ExpandoObject 允许您使用 EventHandler
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