SUMMARY
=======

Although there may be several ways to implement communication
between two executables, this sample illustrates a simple way a server 
and a client application can communicate using IDispatch interfaces.  
This may not be the best method, but it is straight forward to 
implement.  You should consider using dual interfaces as the 
better solution.

The sample consists of two executables.  One (GENERAT.EXE) is a local 
server, and the other (GENCLNT.EXE) is a client of the server.  Both 
client and server are automation servers in that they both support
automation interfaces.  The client application starts the server via
CreateDispatch and thus obtains the servers IDispatch interface.  The 
client then passes it's IDispatch interface to the server using one of 
the servers interface methods.  At this point, two way communication 
between the client and the server is possible.

Be sure to run the server stand-alone once before running it from the
client.  This will register the server and enable client to start it
dynamically.

MORE INFORMATION
================

The GENERAT.EXE local server generates and displays random colors.  It 
can either generate one color each time as it is requested, or it can
continuously generate colors in response to a WM_TIMER message.  The
GENERAT.EXE server can run either stand alone or it can be controlled 
by a client (in this case the GENCLNT.EXE application).  In either case,
the server will be visible and the server's user interface will be 
active.  This means the client and the server will need to communicate
with each other to keep the user interface of the client and server 
synchronized and to process requests from the other.

Below is a list of relavent methods from GENERAT.EXE and GENCLNT.EXE and a 
description of each method.

GENERAT.EXE methods:

BOOL SetAdviseDI(LPDISPATCH DispIToAdvise);

    The client starts the server via CreateDispatch thus obtains the
    IDispatch pointer of the server.  Once the client has the server's
    IDispatch  pointer, it can call this method in the server sending 
    it's own IDispatch pointer.  At this point, Two way communication is
    possible between the client and the server.

void ReleaseAdviseDI();

    The client will call this method to tell the server to release the
    IDispatch pointer of the client.

BOOL AnimateColors();

    Called by the client to request that the server generate colors in
    response to WM_TIMER messages.

void GenNewColor();

    Called by the client to request that the server generate a single
    new color.

GENCLNT.EXE methods:

void SetAnimateUI();

    Called by the server when Animate Colors is chosen via the server 
    UI.  This keeps the Animate Colors menu choice of the client 
    synchronized with that of the server.

void NotifyColorChange(const VARIANT FAR& refColor);

    Called by the server when a color is generated.  Called regardless
    of whether the color was requested by the client or the server.