IMessage Interface

Reference

Definition

Namespace:: System.Runtime.Remoting.Messaging

Assembly:: mscorlib.dll

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Contains communication data sent between cooperating message sinks.

public interface class IMessage

public interface IMessage

[System.Runtime.InteropServices.ComVisible(true)]
public interface IMessage

type IMessage = interface

[<System.Runtime.InteropServices.ComVisible(true)>]
type IMessage = interface

Public Interface IMessage

Derived: System.Runtime.Remoting.Activation.IConstructionCallMessage

System.Runtime.Remoting.Activation.IConstructionReturnMessage

System.Runtime.Remoting.Messaging.ConstructionCall

System.Runtime.Remoting.Messaging.ConstructionResponse

System.Runtime.Remoting.Messaging.IMethodCallMessage

More…

Attributes: ComVisibleAttribute

Examples

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

public:
   MyProxy( Type^ myType )
      : RealProxy( myType )
   {
      
      // RealProxy uses the Type to generate a transparent proxy.
      myMarshalByRefObject = dynamic_cast<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 );
   }

   virtual IMessage^ Invoke ( IMessage^ myIMessage ) override 
    {
      Console::WriteLine( "MyProxy.Invoke Start" );
      Console::WriteLine( "" );
      if ( dynamic_cast<IMethodCallMessage^>(myIMessage) )
            Console::WriteLine( "IMethodCallMessage" );

      if ( dynamic_cast<IMethodReturnMessage^>(myIMessage) )
            Console::WriteLine( "IMethodReturnMessage" );

      Type^ msgType = myIMessage->GetType();
      Console::WriteLine( "Message Type: {0}", msgType );
      Console::WriteLine( "Message Properties" );
      IDictionary^ myIDictionary = myIMessage->Properties;
      
      // Set the '__Uri' property of 'IMessage' to 'URI' property of 'ObjRef'.
      myIDictionary->default[ "__Uri" ] = myURIString;
      IDictionaryEnumerator^ myIDictionaryEnumerator = dynamic_cast<IDictionaryEnumerator^>(myIDictionary->GetEnumerator());
      while ( myIDictionaryEnumerator->MoveNext() )
      {
         Object^ myKey = myIDictionaryEnumerator->Key;
         String^ myKeyName = myKey->ToString();
         Object^ myValue = myIDictionaryEnumerator->Value;
         Console::WriteLine( "\t{0} : {1}", myKeyName, myIDictionaryEnumerator->Value );
         if ( myKeyName->Equals( "__Args" ) )
         {
            array<Object^>^myObjectArray = (array<Object^>^)myValue;
            for ( int aIndex = 0; aIndex < myObjectArray->Length; aIndex++ )
               Console::WriteLine( "\t\targ: {0} myValue: {1}", aIndex, myObjectArray[ aIndex ] );
         }

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

      IMessage^ myReturnMessage;
      myIDictionary->default[ "__Uri" ] = myURIString;
      Console::WriteLine( "__Uri {0}", myIDictionary->default[ "__Uri" ] );
      Console::WriteLine( "ChannelServices.SyncDispatchMessage" );
      myReturnMessage = ChannelServices::SyncDispatchMessage( myIMessage );
      
      // Push return value and OUT parameters back onto stack.
      IMethodReturnMessage^ myMethodReturnMessage = dynamic_cast<IMethodReturnMessage^>(myReturnMessage);
      Console::WriteLine( "IMethodReturnMessage.ReturnValue: {0}", myMethodReturnMessage->ReturnValue );
      Console::WriteLine( "MyProxy.Invoke - Finish" );
      return myReturnMessage;
   }
};

// 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);
   }

   public override IMessage Invoke(IMessage myIMessage)
   {
      Console.WriteLine("MyProxy.Invoke Start");
      Console.WriteLine("");

      if (myIMessage is IMethodCallMessage)
         Console.WriteLine("IMethodCallMessage");

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

      IMessage myReturnMessage;

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

      Console.WriteLine("ChannelServices.SyncDispatchMessage");
      myReturnMessage = ChannelServices.SyncDispatchMessage(myIMessage);

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

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

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

      return myReturnMessage;
   }
}

' Create a custom 'RealProxy'.
Public Class MyProxy
   Inherits RealProxy
   Private myURIString As String
   Private myMarshalByRefObject As MarshalByRefObject

   <PermissionSet(SecurityAction.LinkDemand)> _
   Public Sub New(ByVal myType As Type)
      MyBase.New(myType)
      ' RealProxy uses the Type to generate a transparent proxy.
      myMarshalByRefObject = CType(Activator.CreateInstance(myType), MarshalByRefObject)
      ' Get 'ObjRef', for transmission serialization between application domains.
      Dim myObjRef As ObjRef = RemotingServices.Marshal(myMarshalByRefObject)
      ' Get the 'URI' property of 'ObjRef' and store it.
      myURIString = myObjRef.URI
      Console.WriteLine("URI :{0}", myObjRef.URI)
   End Sub

<SecurityPermissionAttribute(SecurityAction.LinkDemand, Flags:=SecurityPermissionFlag.Infrastructure)> _
   Public Overrides Function Invoke(ByVal myIMessage As IMessage) As IMessage
      Console.WriteLine("MyProxy.Invoke Start")
      Console.WriteLine("")

      If TypeOf myIMessage Is IMethodCallMessage Then
         Console.WriteLine("IMethodCallMessage")
      End If
      If TypeOf myIMessage Is IMethodReturnMessage Then
         Console.WriteLine("IMethodReturnMessage")
      End If
      Dim msgType As Type
      msgType = CObj(myIMessage).GetType
      Console.WriteLine("Message Type: {0}", msgType.ToString())
      Console.WriteLine("Message Properties")
      Dim myIDictionary As IDictionary = myIMessage.Properties
      ' Set the '__Uri' property of 'IMessage' to 'URI' property of 'ObjRef'.
      myIDictionary("__Uri") = myURIString
      Dim myIDictionaryEnumerator As IDictionaryEnumerator = CType(myIDictionary.GetEnumerator(), _
                                                                    IDictionaryEnumerator)

      While myIDictionaryEnumerator.MoveNext()
         Dim myKey As Object = myIDictionaryEnumerator.Key
         Dim myKeyName As String = myKey.ToString()
         Dim myValue As Object = myIDictionaryEnumerator.Value

         Console.WriteLine(ControlChars.Tab + "{0} : {1}", myKeyName, myIDictionaryEnumerator.Value)
         If myKeyName = "__Args" Then
            Dim myObjectArray As Object() = CType(myValue, Object())
            Dim aIndex As Integer
            For aIndex = 0 To myObjectArray.Length - 1
               Console.WriteLine(ControlChars.Tab + ControlChars.Tab + "arg: {0} myValue: {1}", _
                                                              aIndex, myObjectArray(aIndex))
             Next aIndex
         End If

         If myKeyName = "__MethodSignature" And Not Nothing Is myValue Then
            Dim myObjectArray As Object() = CType(myValue, Object())
            Dim aIndex As Integer
            For aIndex = 0 To myObjectArray.Length - 1
               Console.WriteLine(ControlChars.Tab + ControlChars.Tab + "arg: {0} myValue: {1}", _
                                                           aIndex, myObjectArray(aIndex))
            Next aIndex
         End If
      End While

        Dim myReturnMessage As IMessage

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

        Console.WriteLine("ChannelServices.SyncDispatchMessage")
        myReturnMessage = ChannelServices.SyncDispatchMessage(CObj(myIMessage))

        ' Push return value and OUT parameters back onto stack.
        Dim myMethodReturnMessage As IMethodReturnMessage = CType(myReturnMessage, IMethodReturnMessage)
        Console.WriteLine("IMethodReturnMessage.ReturnValue: {0}", myMethodReturnMessage.ReturnValue)

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

        Return myReturnMessage
    End Function 'Invoke
End Class

Remarks

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.

Properties

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

Applies to