向 ExpandoObject 动态添加属性

dynamic x = new ExpandoObject();
x.NewProp = string.Empty;

或者：

var x = new ExpandoObject() as IDictionary<string, Object>;
x.Add("NewProp", string.Empty);

正如 Filip 在这里解释的那样 - http://www.filipekberg.se/2011/10/02/adding-properties-and-methods-to-an-expandoobject-dynamicly/

您也可以在运行时添加方法。

var x = new ExpandoObject() as IDictionary<string, Object>;
x.Add("Shout", new Action(() => { Console.WriteLine("Hellooo!!!"); }));
x.Shout();

这是一个示例帮助类，它转换一个对象并返回一个具有给定对象的所有公共属性的 Expando。

public static class dynamicHelper
    {
        public static ExpandoObject convertToExpando(object obj)
        {
            //Get Properties Using Reflections
            BindingFlags flags = BindingFlags.Public | BindingFlags.Instance;
            PropertyInfo[] properties = obj.GetType().GetProperties(flags);

            //Add Them to a new Expando
            ExpandoObject expando = new ExpandoObject();
            foreach (PropertyInfo property in properties)
            {
                AddProperty(expando, property.Name, property.GetValue(obj));
            }

            return expando;
        }

        public static void AddProperty(ExpandoObject expando, string propertyName, object propertyValue)
        {
            //Take use of the IDictionary implementation
            var expandoDict = expando as IDictionary<String, object>;
            if (expandoDict.ContainsKey(propertyName))
                expandoDict[propertyName] = propertyValue;
            else
                expandoDict.Add(propertyName, propertyValue);
        }
    }

用法：

//Create Dynamic Object
dynamic expandoObj= dynamicHelper.convertToExpando(myObject);
    
//Add Custom Properties
dynamicHelper.AddProperty(expandoObj, "dynamicKey", "Some Value");

我认为这会添加所需类型的新属性，而无需设置原始值，例如在类定义中定义属性时

var x = new ExpandoObject();
x.NewProp = default(string)