ID Number: Q74807
3.10
WINDOWS
Summary:
At the Windows operating system level, both object linking and
embedding (OLE) and dynamic data exchange (DDE) are protocols for
exchanging data and sending commands between applications. For Windows
versions 3.0 and 3.1, neither the OLE libraries nor the Dynamic Data
Exchange Management Library (DDEML) depend on special interprocess
communications (IPC) mechanisms provided by the operating system.
Rather, both OLE and DDE depend on the Windows messaging facility.
At the Windows operating system level, the OLE protocol is built on
top of the DDE protocol. More specifically, the OLE protocol is
largely a set of DDE Execute command strings that follow a
conventional syntax.
At the application level, a function-based application program
interface (API) is available for both OLE and DDE. For OLE, this API
is provided to clients by the OLECLI.DLL file and to servers by the
OLESVR.DLL file. For DDE, this API is provided by the DDEML.DLL file.
Despite the fact that OLE uses DDE as its transport mechanism, the
present implementation of OLE is independent of the DDEML. This does
not signify any functional or performance deficiencies of DDEML.
Because the OLE libraries and DDEML were implemented in parallel, the
schedule did not allow for this version of the OLE libraries to use
DDEML.
It is quite likely that future versions of the OLE libraries will use
DDEML rather than directly coding DDE messages.
Additional reference words: OLE DDEML 3.10 3.1