You can convert a dynamic object to ExpandoObject (C #)

Question

I get a dynamic object of type "Sealed class" from the api driver (in dll). I want to decorate this object with several additional properties.

I would like to do something in mind:

public void expandIT(dynamic sealedObject) { ExpandoObject expand = new ExpandoObject(sealedObject); expand.time = DateTime.Now(); etc.... } 

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UPDATE

I like the JCL solution. But for what I wanted to do, it was easier to create an ExpandoObject, and then insert an object with a dynamic private class as a child property, and then add my properties to the parent ExpandoObject. Thanks to JCL, I was able to freeze my brain on how to do this. I

Answer 1

Nope. The dynamic object does not apply the type at compile time, but does not magically make your object extensible (unless it is an ExpandoObject ).

However, you can create some kind of wrapper or proxy using DynamicObject ... something like:

 public class ExpandedObjectFromApi : DynamicObject { private Dictionary<string, object> _customProperties = new Dictionary<string, object>(); private object _currentObject; public ExpandedObjectFromApi(dynamic sealedObject) { _currentObject = sealedObject; } private PropertyInfo GetPropertyInfo(string propertyName) { return _currentObject.GetType().GetProperty(propertyName); } public override bool TryGetMember(GetMemberBinder binder, out object result) { var prop = GetPropertyInfo(binder.Name); if(prop != null) { result = prop.GetValue(_currentObject); return true; } result = _customProperties[binder.Name]; return true; } public override bool TrySetMember(SetMemberBinder binder, object value) { var prop = GetPropertyInfo(binder.Name); if(prop != null) { prop.SetValue(_currentObject, value); return true; } if(_customProperties.ContainsKey(binder.Name)) _customProperties[binder.Name] = value; else _customProperties.Add(binder.Name, value); return true; } } 

And then you can use it like:

 dynamic myExpandedObject = new ExpandedObjectFromApi(sealedObject); 

This should return the original properties of the object, if found, or if there is no property of this name in the original object, it will add it as the "custom" property.

I made the code in the Qaru editor and probably made a lot of mistakes, it is not suitable for copy / paste, and it needs a ton of error checking (it is also necessary to implement fields and methods if the resulting object has them). Just wrote this to get the main idea.

You can also add a special property (for example, something like WrappedObject ) and write it to TryGetMember to return the original object.