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[wxWidgets.git] / docs / latex / wx / ddeclint.tex

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

A wxDDEClient object represents the client part of a client-server DDE
(Dynamic Data Exchange) conversation.

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-overridden \helpref{wxDDEClient::OnMakeConnection}{wxddeclientonmakeconnection} member can return
a wxDDEConnection of the required class, when a connection is made.

This DDE-based implementation is
available on Windows only, but a platform-independent, socket-based version
of this API is available using \helpref{wxTCPClient}{wxtcpclient}.

\wxheading{Derived from}

wxClientBase\\
\helpref{wxObject}{wxobject}

\wxheading{Include files}

<wx/dde.h>

\wxheading{See also}

\helpref{wxDDEServer}{wxddeserver}, \helpref{wxDDEConnection}{wxddeconnection}, 
\helpref{Interprocess communications overview}{ipcoverview}

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

\membersection{wxDDEClient::wxDDEClient}\label{wxddeclientctor}

\func{}{wxDDEClient}{\void}

Constructs a client object.

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

\func{wxConnectionBase *}{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{wxConnectionBase *}{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, a 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}{wxconnectiononadvise}. You may also want to
store application-specific data in instances of the new class.

\membersection{wxDDEClient::ValidHost}\label{wxddeclientvalidhost}

\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.