IMessage Interface
Assembly: mscorlib (in mscorlib.dll)
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 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 'New <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 'MyProxy
// Create a custom 'RealProxy'.
/** @attribute SecurityPermission(SecurityAction.Demand, Flags = SecurityPermissionFlag.Infrastructure) */
public class MyProxy extends RealProxy
{
private String myURIString;
private MarshalByRefObject myMarshalByRefObject;
public MyProxy(Type myType)
{
super(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.get_URI();
Console.WriteLine("URI :{0}", myObjRef.get_URI());
} //MyProxy
public IMessage Invoke(IMessage myIMessage)
{
Console.WriteLine("MyProxy.Invoke Start");
Console.WriteLine("");
if (myIMessage instanceof IMethodCallMessage) {
Console.WriteLine("IMethodCallMessage");
}
if (myIMessage instanceof IMethodReturnMessage) {
Console.WriteLine("IMethodReturnMessage");
}
Type msgType = myIMessage.GetType();
Console.WriteLine("Message Type: {0}", msgType.ToString());
Console.WriteLine("Message Properties");
IDictionary myIDictionary = myIMessage.get_Properties();
// Set the '__Uri' property of 'IMessage' to 'URI' property of 'ObjRef'.
myIDictionary.set_Item("__Uri", myURIString);
IDictionaryEnumerator myIDictionaryEnumerator =
(IDictionaryEnumerator)(myIDictionary.GetEnumerator());
while (myIDictionaryEnumerator.MoveNext()) {
Object myKey = myIDictionaryEnumerator.get_Key();
String myKeyName = myKey.ToString();
Object myValue = myIDictionaryEnumerator.get_Value();
Console.WriteLine("\t{0} : {1}", myKeyName,
myIDictionaryEnumerator.get_Value());
if (myKeyName.Equals("__Args")) {
Object myObjectArray[] = (Object[])myValue;
for (int aIndex = 0; aIndex < myObjectArray.length; aIndex++) {
Console.WriteLine("\t\targ: {0} myValue: {1}",
(Int32)aIndex, myObjectArray.get_Item(aIndex));
}
}
if (myKeyName.Equals("__MethodSignature") && null != myValue) {
Object myObjectArray[] = (Object[])myValue;
for (int aIndex = 0; aIndex < myObjectArray.length; aIndex++) {
Console.WriteLine("\t\targ: {0} myValue: {1}",
(Int32)aIndex, myObjectArray.get_Item(aIndex));
}
}
}
IMessage myReturnMessage;
myIDictionary.set_Item("__Uri", myURIString);
Console.WriteLine("__Uri {0}", myIDictionary.get_Item("__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.get_ReturnValue());
Console.WriteLine("MyProxy.Invoke - Finish");
return myReturnMessage;
} //Invoke
} //MyProxy
Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.