IMessage Interface


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Contains communication data sent between cooperating message sinks.

Namespace:   System.Runtime.Remoting.Messaging
Assembly:  mscorlib (in mscorlib.dll)

public interface IMessage


Gets an IDictionary that represents a collection of the message's properties.

Message sinks that use IMessage can be placed in the client sink chains or in the server sink chains. A message object is passed from message sink to message sink through the chain, and carries a set of named properties such as action identifiers, envoy information, and parameters.

An object that implements the IMessage interface meets the minimum qualifications to be considered a message object. The exact object received by a message sink does not have to be passed on to the next sink, but this is often the case.

Although the objects in the property bag do not have to be serializable, the message sink implementer needs to consider this, since the properties that flow out of the application domain must be serializable.

// Create a custom 'RealProxy'.
public class MyProxy : RealProxy
   String myURIString;
   MarshalByRefObject myMarshalByRefObject;   

   public MyProxy(Type myType) : base(myType)
      // RealProxy uses the Type to generate a transparent proxy.
      myMarshalByRefObject = (MarshalByRefObject)Activator.CreateInstance((myType));
      // Get 'ObjRef', for transmission serialization between application domains.
      ObjRef myObjRef = RemotingServices.Marshal(myMarshalByRefObject);
      // Get the 'URI' property of 'ObjRef' and store it.
      myURIString = myObjRef.URI;
      Console.WriteLine("URI :{0}", myObjRef.URI);

   [SecurityPermissionAttribute(SecurityAction.LinkDemand, Flags=SecurityPermissionFlag.Infrastructure)]
   public override IMessage Invoke(IMessage myIMessage)
      Console.WriteLine("MyProxy.Invoke Start");

      if (myIMessage is IMethodCallMessage)

      if (myIMessage is IMethodReturnMessage)

      Type msgType = myIMessage.GetType();
      Console.WriteLine("Message Type: {0}", msgType.ToString());
      Console.WriteLine("Message Properties");
      IDictionary myIDictionary = myIMessage.Properties;
      // Set the '__Uri' property of 'IMessage' to 'URI' property of 'ObjRef'.
      myIDictionary["__Uri"] = myURIString;
      IDictionaryEnumerator myIDictionaryEnumerator = 
         (IDictionaryEnumerator) myIDictionary.GetEnumerator();

      while (myIDictionaryEnumerator.MoveNext())
         Object myKey = myIDictionaryEnumerator.Key;
         String myKeyName = myKey.ToString();
         Object myValue = myIDictionaryEnumerator.Value;

         Console.WriteLine("\t{0} : {1}", myKeyName, 
         if (myKeyName == "__Args")
            Object[] myObjectArray = (Object[])myValue;
            for (int aIndex = 0; aIndex < myObjectArray.Length; aIndex++)
               Console.WriteLine("\t\targ: {0} myValue: {1}", aIndex, 

         if ((myKeyName == "__MethodSignature") && (null != myValue))
            Object[] myObjectArray = (Object[])myValue;
            for (int aIndex = 0; aIndex < myObjectArray.Length; aIndex++)
               Console.WriteLine("\t\targ: {0} myValue: {1}", aIndex, 

      IMessage myReturnMessage;

      myIDictionary["__Uri"] = myURIString;
      Console.WriteLine("__Uri {0}", myIDictionary["__Uri"]);

      myReturnMessage = ChannelServices.SyncDispatchMessage(myIMessage);

      // Push return value and OUT parameters back onto stack.

      IMethodReturnMessage myMethodReturnMessage = (IMethodReturnMessage)
      Console.WriteLine("IMethodReturnMessage.ReturnValue: {0}", 

      Console.WriteLine("MyProxy.Invoke - Finish");

      return myReturnMessage;

.NET Framework
Available since 1.1
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