expandoobject

In the following sample, x.propertyX works fine, whereas y.propertyX gives me a Microsoft.CSharp.RuntimeBinder.RuntimeBinderException , complaining 'propertyX' is not defined in 'object'. The CreateDynamic method in the Program class (shown below) and the one in Class1 (not shown) are exactly the same, but Class1 is in a different project from Program. If I move Class1 into Program's project, everything works fine. class Program { public static object CreateDynamic() { return new { propertyX = "asdf" }; } static void Main(string[] args) { dynamic x = CreateDynamic(); Console.WriteLine(x

I am getting an dynamic object of type "Sealed Class" from a driver api (in dll). I want to decorate this object with a few additional properties. I would like to do something to the effect of: public void expandIT(dynamic sealedObject) { ExpandoObject expand = new ExpandoObject(sealedObject); expand.time = DateTime.Now(); etc.... } UPDATE I like JCL's solution. But for what I wanted to do, it was easier to create a ExpandoObject and then embed the Dynamic sealed class object as a child property, and then add my properties to the parent ExpandoObject. Thanks JCL, I was in brain-freeze as to

Something caught me by surprise when looking into C# dynamics today (I've never used them much, but lately I've been experimenting with the Nancy web framework). I found that I couldn't do this: dynamic expando = new ExpandoObject(); expando.name = "John"; Console.WriteLine(expando["name"]); The last line throws an exception: Cannot apply indexing with [] to an expression of type 'System.Dynamic.ExpandoObject' I understand the error message, but I don't understand why this is happening. I have looked at the documentation for ExpandoObject and it explicitly implements IDictionary<,> and thus

I've got an ExpandoObject that I'm sending to an external library method which takes an object. From what I've seen this external lib uses TypeDescriptor.GetProperties internally and that seems to cause some problems with my ExpandoObject. I could go with an anonymous object instead and that seems to work but it much more convenient for me to use the ExpandoObject. Do I need to construct my own DynamicObject and take care of it myself by implementing ICustomTypeDescriptor or am I missing something here. Ideas? Update Besides the answer by somedave below (as per the comments), I added this

Is there any way to use the new dynamic features in the 4.0 framework like ExpandoObject in VB.NET without setting Option Strict Off ? With C#, you lose type safety only with the variables you specifically declare as dynamic . But with VB, the only way I've found to use these features is with the old Option Strict Off trick that's been in VB.NET since the beginning. Without Option Strict, everything in the file is polluted with fuzzy typing like so: Option Explicit On Option Strict Off Option Infer On Partial Public Class ClassX Public Sub TestDynamic() Dim dyn As Object = New System.Dynamic

I'm trying to use a System.Dynamic.ExpandoObject so I can dynamically create properties at runtime. Later, I need to pass an instance of this object and the mechanism used requires serialization. Of course, when I attempt to serialize my dynamic object, I get the exception: System.Runtime.Serialization.SerializationException was unhandled. Type 'System.Dynamic.ExpandoObject' in Assembly 'System.Core, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' is not marked as serializable. Can I serialize the ExpandoObject? Is there another approach to creating a dynamic object that is

Am I doing something wrong, or is the following code really not possible? dynamic x = new ExpandoObject { Foo = 12, Bar = "twelve" }; If this really isn't possible, is there another one-line way to instantiate an ExpandoObject with two properties? Why would the C# team opt to disallow the same initialization syntax as for regular objects, anonymous objects, and enumerables/lists? Update I asked this question because I was trying show a Pearl enthusiast the cool new dynamic features of C#, but then I was stalled by not being able to do what I thought was a logical instantiation of an