How to use Reflection on a COM object?

Question

I am trying to do a Reflection in a program, however, when the time to pick up the type of the object (Which is necessary for the Reflection) is returning "System. __Comobject", and this is not useful. The method I tried was the following:

Type tipo = simObjects.GetType();

The same feedback happens when I try with the typeof() method; I researched and found the following method:

Type tipo = Microsoft.VisualBasic.Information.TypeName(simObjects);

It returns the right type, but in string format, (it from the error in the above code "Cannot implicit Convert "String" to "System.Type", but I swapped Type for String and it returned the type name) some genius can tell me how I can return in Type form?

Answer 1

Is not possible.

System.__COMObject is a class declared as internal and all its methods are exposed by System.Runtime.InteropServices.Marshal. Therefore, this class is nothing more than a wrapper for the COM object, not having a type . Net derivative that can be obtained by the method Object.GetType().

If you want to see more about this class, I recommend taking a look at the source code:

• Mono: System. __Comobject.Cs
• .NET: System. __Comobject.Cs

Editing:

According to your comment, what you want then is to get RTTI from the COM library. C# does not allow this type of direct interaction with RTTI of unmanageable objects, so what to do?

1. What language your COM library was written in. It’s usually C++, but it can be written in Object Pascal as well, for example.

2. Was the COM library compiled with RTTI? If not, there is nothing that can be done but cry for the library developers to compile it with RTTI. Why? Because without RTTI, there is simply no way to re-flect an object.

3. Build a library in the same language as your COM library that does the Reflection for you. Using P/Invoke you interact with it within C#. Note that you will never have an object of the type System.Type, because this object only exists in manageable codes, which is not the case for your COM library.

Maybe just build a structure that encapsulates the std::type_info returned by operator typeid (if C++ is the language of the COM library, of course), and building the methods to get this value from your COM class is enough.

The RTTI analysis library is not complicated no (or does not seem to me at first), and needs only a few methods implemented according to your need. Compared to the other solutions I presented in the comments, it is a fraction of the complexity/effort, no doubt.

Answer 2

It may not have been so clear what I wanted, but I was able to sort of resolve it by forcing reflection and it turned out there was no need to catch the guy.

foreach(PropertyDescriptor descricao in TypeDescriptor.GetProperties(ObjetoCOM))
{
    if(descricao.Name == "Nome do atributo")
    {
        foreach(PropertyDescriptor descricao2 in TypeDescriptor.GetProperties(descricao))
        {
           if(descricao.Name == "Nome do atributo")
           {
           }
        } 
    }
}

This code returns the name of the attributes, for example, if my Objetocom has the following attributes:

int idade;
string nome;
Filho filho;

and son has:

int idade;
string nome;

in the first loop, the Description. Name will be "age", "name" and "son", and in the second (assuming the condition is true with the child), "age" and "name".