\section{\class{wxDDEClient}}\label{wxddeclient}

\overview{Interprocess communications overview}{ipcoverview}

A wxDDEClient object represents the client part of a client-server DDE
(Dynamic Data Exchange) conversation (available in {\it both}\/
Windows and UNIX).

To create a client which can communicate with a suitable server,
you need to derive a class from wxDDEConnection and another from wxDDEClient.
The custom wxDDEConnection class will intercept communications in
a `conversation' with a server, and the custom wxDDEServer is required
so that a user-overriden \helpref{wxDDEClient::OnMakeConnection}{wxddeclientonmakeconnection} member can return
a wxDDEConnection of the required class, when a connection is made.

\wxheading{Derived from}

wxDDEObject

\wxheading{See also}

\helpref{wxDDEServer}{wxddeserver}, \helpref{wxDDEConnection}{wxddeconnection},
the chapter on interprocess communication in the user manual, and
the programs in {\tt samples/ipc}.

\latexignore{\rtfignore{\wxheading{Members}}}

\membersection{wxDDEClient::wxDDEClient}

\func{}{wxDDEClient}{\void}

Constructs a client object.

\membersection{wxDDEClient::MakeConnection}\label{wxddeclientmakeconnection}

\func{wxDDEConnection *}{MakeConnection}{\param{const wxString\& }{host}, \param{const wxString\& }{service}, \param{const wxString\& }{topic}}

Tries to make a connection with a server specified by the host
(machine name under UNIX, ignored under Windows), service name (must
contain an integer port number under UNIX), and topic string. If the
server allows a connection, a wxDDEConnection object will be returned.
The type of wxDDEConnection returned can be altered by overriding
the \helpref{wxDDEClient::OnMakeConnection}{wxddeclientonmakeconnection} member to return your own
derived connection object.

\membersection{wxDDEClient::OnMakeConnection}\label{wxddeclientonmakeconnection}

\func{wxDDEConnection *}{OnMakeConnection}{\void}

The type of \helpref{wxDDEConnection}{wxddeconnection} returned from a \helpref{wxDDEClient::MakeConnection}{wxddeclientmakeconnection} call can
be altered by deriving the {\bf OnMakeConnection} member to return your
own derived connection object. By default, an ordinary wxDDEConnection
object is returned.

The advantage of deriving your own connection class is that it will
enable you to intercept messages initiated by the server, such
as \helpref{wxDDEConnection::OnAdvise}{wxddeconnectiononadvise}. You may also want to
store application-specific data in instances of the new class.

\membersection{wxDDEClient::ValidHost}

\func{bool}{ValidHost}{\param{const wxString\& }{host}}

Returns TRUE if this is a valid host name, FALSE otherwise. This always
returns TRUE under MS Windows.