Get the AppDomain of object

Question

Is there any way to determine in which AppDomain was an object or ObjectHandle instance created?

Answer 1

An object from another app domain is a transparent proxy. It is possible to get the real proxy and access the private field that contains the domain id:

public static int GetObjectAppDomain(object proxy)
{
    RealProxy rp = RemotingServices.GetRealProxy(proxy);
    int id = (int)rp.GetType().GetField("_domainID", BindingFlags.Instance|BindingFlags.NonPublic).GetValue(rp);
    return id;
}

If the list of possible app domains isn't known, here is a way to get the list of all app domains.